In the hebrew article of the light bulb in the hebrew Wikipedia (I have no reliable english source), are written that:
"A documentary called "light bulb conspiracy: the untold story of planned downtime" argued that the joint decision of the light bulbs Manufacturers led to a "planned obsolescence" of the bulb within a constant use much shorter than it could have been from existing technology, to impose the consumer to purchase new bulbs in a relatively short time periods. The film alleges that the modern light bulb is designed to operate around 1,000 hours, however, the first electric light bulb Edison's late 19th century, already worked longer, 1,500 hours continuously, and later lamps operated for about 2,500 hours continuously. According to the film, in 1924 was established in Geneva a cartel of large corporations in producing light bulbs, that one of their first decisions was operating time of 1,000 hours for a simple electric bulb. As an example of a planned obsolescence, mentioned many times certain incandescent bulb nicknamed the "Centennial Light", which is used almost continuously, for at least 110 years, the fire station in Livermore, California." (Translated from the hebrew article of Wikipedia).

Have you know that the 1000 hours average life of the incandescent lamps, is a planned obsolescence? Incandescent lamps can, if built well, to last as long as LEDs and Induction (100,000 hours), even if operated with a 2700K color temperature.

Other examples of lamps and gears that are victims to a planned obsolescence:
1. Electronic ballasts (Components [Usually the electrolytic capacitor] that desinged to blow, burn or explode after a preplanned amount of operation hours).
2. LED drivers, LEDs and solid state lighting (Similar to electronic ballasts in the case of LED drivers. LEDs that designed to dim or burn after a preplanned amount of operation hours).
3. Long T5 fluorescent lamps (Electrodes planned to deplate from emitter after a preplanned amount of operation hours).
4. Low mercury fluorescent lamps (Philips ALTO)(The very low mercury dosing is done MAINLY as a mechanism for planned obsolescence of the lamp and NOT for environmental reason like the lighting companies and the governments says, to get the lamp mercury starved after a preplanned amount of operating time).
5. CFLs (Similar to incandescent lamps and electronic ballasts).

more like 1,000 hours life is a best medium between efficiency and life, long life incandescent are available here and of course have lower color temperature, usually long life/ rough service ones are something like 7,000 HR

I think that based of all the information, without the idea of planned obsolescence, it is possible with modern technologies, to make an incandescent lamp, that would last 100 years and yet to produce a 2700K regular incandescent color, and the same efficiency as an 1000 hours incandescent lamp.
Is the Centennial Light lamp, was underdriven in order to achieve the world's longest lamp life of 110 years (And it is still burning today) in an almost continuous use?
Without the Phoebus cartel, incandescent lamps could have outlast LEDs and induction to become the most durable electric artifical light source.

1,000 hour "Standard" bulbs are definitely planned obsolescence. 2,000 hour "Double Life" bulbs have been available for quite some time, and they offer nearly the same light output as 1,000 hour bulbs.

These "plots" are all scam...

The (quality) lightbulb lifetime is dictated by the filament evaporation rate and that is strongly linked to the operating temperature and the eventual atmosphere. But the same factors influence the lamp efficacy and safety (behavior at EOL, during overvoltage events,...), but mostly it goes against each other.

So the lightbulb design is matter of finding the best compromise between life, efficacy and safety, in order to provide lowest operating cost (new bulb plus electricity plus costs related to maintenance) solution (where the inconvenience with replacing a bulb and the safety related risks are translated into a cost as well).
These effects are known since the invention of gas filled lamp, but the importance of each of the three parameters changed over the century of lightbulb use:
Initially manufacturing the lightbulb was very expensive, so with such condition it make sense to design the bulb for linger life and sacrifice the efficacy. Anyway the efficacy (measured in lumen-hours per given amount of coal) was way superior compare to other light sources, as kerosene or gas lamps.

But over the century the automated machinery allowed the bulbs to be produced very cheaply, so the cost of the new bulb become negligible, so it make better sense to prefer the efficacy and swallow the shorter life. With energy cost of more than 10times the lamp purchase cost it really does not make sense to sacrifice 1/2 of the efficacy for 1000hour life for normal household use.
Of course, for some applications the maintenance costs and the costs related to reliability remained, therefore we still see lamps with designed median life of 8..15khours (e.g. signal lamps; by the way these are not subjected to the EU ban)

And the use of gas filling (improving the efficacy and life) bring in the new thread and that is arcing and resulting bulb explosions at the EOL or during mains overvoltage events. To keep these under control, the pressure and gas composition should be modified, worsening the results of life/efficacy. These problems are mainly related to higher operating voltages, 24V lamp don't care, but 230V lamp become quite affected. And this is the reason, why EU 230V lamps have ~20..30% lower efficacy than 120V US lamps, simply because the 120V have less potential to cause arcing...

Of course when the manufacturing quality is less under control, so the designed parameters vary in more extend, resulting production yield poorer results (shorter median life or lower efficacy or more frequent bulb explosions than), but may yield to lower production cost...

Medved: But there are also planned obsolescences that done intentionally, namely ONLY to cause the consumer to buy more and more bulbs, and not to make a compromise between reliability, efficiency, safety, and pursche and maintenance cost.

Low mercury fluorescent lamps is an example: Despite the EPA classes fluorescent lamps with less than 1mg amount of mercury as a non hazarodus waste, full 5mg mercury fluorescent lamps aren't more dangerous to the people the environment when broken or disposed than low mercury fluorescent lamps. Reduction of mercury in fluorescent lamps don't lowers their price (If their prices are inded lower, this is related to other reasons such as low building quality and not to the amount of mercury dosing), and their environmental risks, but these lamps goes mercury starved within a year max, and are much less efficient than full dose mercury lamps.

In other products, unrelated to lighting, there are also intentionally planned obsolescence mechanisms:

Probably the most famous examples of products that have a built in (Intentionally) planned obsolescences, are Apple devices and inkjet printers (Especially HP printers):

1. Apple devices: IPhone, IPod, IPad, Macbook Air, Macbook Pro Retina, all have a built in planned obsolescence in the form of unremovable batteries, that programmed to disable themselves after a specific number of hours or charges, and that its replacement is more expensive than a new product. When the battery reaches EOL, the entrie device needs to be replaced by a new one. There is no compromises here between reliability, efficiency, safety, and purchase and maintenance cost of Apple products, as Apple devices are considerably more expensive than competiting devices (One of the reasons why I hate Apple and their IPhone). Apple programmed their devices to fail after a specific time.

2. Inkjet printers: Many HP inkjet printers have a built in chip that disable the entrie printer after a programmed amount of time or amount of printed pages. I'm suspecting that my HP Deskjet 6122 for example, was a victim to such a planned obsolescence, where after betwenn 1 and 2 years it suddenly gone dead for no reasons, when in the previous day, operated PERFECT, LIKE A NEW.
HP and Epson inkjet printers tends to refuse printing if one of their ink cartridges becomes empty. Some printers uses all print cartridges when printing B/W, to cause the user to replace the color cartridges even if he print ONLY in B/W (Several printers even go far, and consume ink for no reasons, either by unnecessary print head cleanings or just without a real reasons to use ink.
HP and probably also Epson print cartridges have an internal chip that disables them after a programmed period of time (Called by HP "Print cartridge expiration date"). Ink of course can have an infinite life if well stored (Even inside the printer print head), unlike food and drugs.

In appliances, there are also good examples for bulit in (intentional) planned obsolescences:

1. Household inverter (Variable output) air conditioners: This variable output (Inverter) technology is relevat and have actual adventages only in the industrial air conditioning systems. In all that related to household air conditioning, the purpose of the inverter technology is to act as a mechanism of an intentional planned obsolescence with no compromises, as inverter air conditioners are much more expensive, both initial and maintenance, than a fixed output (Regular) air conditioners, but even the expensive ones are much less reliable than the cheaper regular air conditioners, and this is true also for the japanese inverter air conditioners (If a japanese inverter air conditioner is very reliable, because of the very high quality production in Japan, this means that a hypothetical fixed output air conditioner, will have nearly infinitie lifetime with almost zero failures [In automobile, this is exactly what happened with the Peugeot 404 passanger car. That car model, had essentially an infinite lifetime with zero failures, and because there were no fixing calls form the consumers to the company, this model was discontinued and replaced by his less reliable successor]).

2. Electronics/computerized in refrigerators, freezers, ovens and water dispensers: The only real purpose for the electronic control panels and/or the touch screens of electronic/computerized refrigerators, freezers, ovens and water dispensers is as a mechanism of an intentional planned obsolescence: These appliances are much more expensive than their mechanical controlled counterparts, but are much less reliable and can survive at least up to 3 years max in the ideal cases (Compared to 6-10s of years of the mechanical controlled refrigerators, freezers, ovens and water dispensers).

You should really not believe so much to all the conspiration theories.

In all the cases there are compromises to be made, so when you stress one aspect, you should not be mad to get worse results on the other aspects.

Some facts:

With the incandescents you may check, then they all the time lay quite spot on the same efficacy vs lifetime curve, with only some improvement over time (the technology matured about 50years ago, so since that you can not expect much to improve, they could be only tuned for different objective)

The variable speed vs classic AC's: The complex electronic of the variable speed units indeed cost extra money and lower reliability, but it's purpose is to save the power needed to cool the home. I live in quite cold area, so we have only maximum two hot months in the year where the AC is useful and yet the yearly electricity consumption of a typical household unit (one compressor, three inner units, 6kW of cooling power total) cost here about twice the purchase cost of the complete system.
So about 20% of energy savings pay off even with twice as expensive units with only 5 years life compare to 10 years of the "classic". In countries with hot climate this difference would be much greater. So even when more expensive and less reliable, they simply pay off.

Extreme low mercury fluorescents in the US (ALTO's,...) are an answer to the (questionable) EPA rule about <1mg lamps not classifying as dangerous waste. The problem is not as much in homes, where the disposal into recycling centers is in most countries free of charge, there it indeed would not make much sense.
But in the commercial sector the company have to pay quite a lot of money to legally dispose of any hazardous waste. They can not go around as easily, as they are subject of audits from the government agencies, where virtually for each purchased lamp they have to prove they disposed of it properly (the purchased amount is compared with a bill from the certified waste management company). Such system is present (with only minor variations) in most of the civilized world. So in such legal environment is a huge cost benefit to avoid generating the dangerous waste as much as possible. So when some i***t in the government classify extra low Hg dose as non-hazardous, companies utilize this as a way to save on the waste disposal costs. Therefore Philips offered a lamp meeting these criterias, even if that mean way shorter life and worse reliability. So the ALTO's become simply cheaper in TCO, so are so popular. Commercial companies exist to make money in the first place, so they always choose the cheapest way. It is the duty of rule-makers (so the governments) to ensure, than all expenses, even the side ones (on the environment,...) are billed to the commercial companies, so they take care of it in a reasonable way.

Integrated vs replaceable batteries:
Integrated batteries really mean the practical lifetime of the device is limited by the battery, but the integration save quite significant amount of usable space inside the product, so allow way more compact overall design. With removable battery none of the MAcBook's, nor i-Phones could be made so thin, it won't be simply possible (with the thermal management,...).
If the limited product life is the cost to pay for it's compactness? Apparently yes, customers prefer it.
If I want to pay such cost as well? It depend: Standard LiIon battery life is about three years, normal life of the computer devices is about four years (till components start to fail), with the mobile phones it is even shorter (because the user want new features in the meantime available in the new models, so the older loose it's value). So we are in fact talking about maximum 25% reduction in the product lifetime being the cost of the compactness. For a device to be carried all the time with me, honestly not as much.
Note: I'm not an "Apple fan" (more the opposite, due to how they behave in recent years), but the evident popularity of their products is undisputable proof, than people are willing to pay the costs.

The inks: I don't know, how do you came to the conclusion about a thing, what is supposed to dry very quickly when used would not dry out in the printer head assembly. They may not age as much when sealed in the original packaging, but the printing head could not be made so well sealed, how it could then throw the ink out?
The ink cost vs printer come from the strategy HP choose: They give the printer for free (the sale cost with full cartridges is equivalent to the sale cost of the packed in consumables) and collect the money via expensive selling the consumables (even when these are in reality cheap to manufacture). So they are so expensive and their use is quite accurately measured: The cartridge is dosed so, it make the declared use with all the manufacturing and HW tolerances involved. Because the real ink consumption of the print head is quite difficult to predict and so have quite large spread, they overdose the ink content. But the monitoring chip is able to monitor the usage perfectly, so it is set exactly to the declared level.
Otherwise the printer itself would have to cost many times more, HP make printers to make money for their shareholders in the first place, so do not expect the total cost to be lower in some other scenario. And apparently, consumers prefer the model of having the total cost distributed over time than paying it all at once and then have cheap consumables. Otherwise HP simply would not use this business model for the ink-jets.

I really hate printers. I have opened "empty" Epson ink cartridges that were more than 1/2 full. They also often come with some horribly bad drivers that are actually adware: ads for cartridges are displayed every time you print a document (on Windows anyway - I don't normally use that unless I have to).

Color printers (both inkjet and laser) also print an almost invisible pattern on every page that identifies the printer, so that the governments can track you. I really hate this "feature". Fortunately, my 20 year old dot matrix printer does none of this, an a drop of acetone is all it takes to renew the ribbon cartridge when it does dry

I bought a new phone last month (my old GSM phone from 2005 really wasn't usable anymore, too many buttons had stopped working, plus GSM coverage of my parents town has been getting worse recently, I don't know why, poor maintenance perhaps (3G coverage is great). It has a removable battery, yet it still it no bigger than the average smart phone and still has a dual core 1 GHz CPU and 2/3rds the pixel count of my netbook.

It would not surprise me if RoHS at least partly was created for the benifit of planned obsolescence: remove lead from solder so that tin whiskers grow and decrease the lifetime of electronics, but more importantly, remove hazardous chemicals so that it could be (partially) claimed that building short-lived stuff is not an environmental problem even if they are disposed of incorrectly.

Color printers (both inkjet and laser) also print an almost invisible pattern on every page that identifies the printer, so that the governments can track you. I really hate this "feature". Fortunately, my 20 year old dot matrix printer does none of this, an a drop of acetone is all it takes to renew the ribbon cartridge when it does dry

According to Wikipedia, I tought that only color laser printer and color copiers, prints this steganographic invisible pattern.
Dot matrix printers in full size, were really out of service in Israel, and can be found only in some cash registers.

I really hate printers. I have opened "empty" Epson ink cartridges that were more than 1/2 full. They also often come with some horribly bad drivers that are actually adware: ads for cartridges are displayed every time you print a document (on Windows anyway - I don't normally use that unless I have to).

Good that I bought my Canon Pixma iP5300. No ads, the printer allows me to continue to print when one of the cartridges declared as empty, and even use the one that declared as empty (Simply, the message that appears in my driver that a specific cartridge is empty, allows me to continue printing. My Canon printer is almost 4 years old, and its only failure was its print head that was damaged by me, when I manually cleaned it with a toilet paper. Newpan charged me for a ~500NIS, for a new print head.