The arctube quartz has to handle way more than just some distributed heat, so using anything that may affect the material is not that good idea. The outer bulb would need to be used anyway and it would have to be quartz as well because of the temperatures, so it is easier to really optimize the arctube material to work best for the arctube and handle the rest in the way less stressed outer.

It is just abuse of nonexpert buyers, a result of predatory marketing and completely absent consumer protection.
A way to make the things really cheap even when that means it can barely survive a single lamp (as a failing lamp tends to kill the starter, that is the reason why both needs to be replaced together) and hide that from the customers.

For the rectification cutout it does matter what is the exact ballast output topology, whether it can deliver DC current or not. If yes (e.g. when using full bridge output stage), there is no need for rectification cutout, rectification is not endangering anything. And given the square wave frequency (150..400Hz), even when it lights only for one halfwave, the resulting flicker won't be that a problem.
But if the output stage is a halfbridge against a center point between capacitors, the ballast must shut off when the center point is imbalanced too much in order to protect those capacitors from overvoltage (they are designed so the bus voltage is split among them, imbalance causes one of them getting way higher voltage and so may exceed its rating).
Some halfbridge ballasts may address this by just adjusting the duty ratio of the square wave, so if one polarity yields lower current, it is let to flow the longer time and maintaining the center voltage this way. Then there wil be some limits set how far the duty ratio may go, shutting down when that would be too much.

@fluorescent lover 40, bring that weather here! haha
I've been to California when Ohio was still in winter conditions, in April of 2014. The weather was far different there than here in Ohio.
It was like stepping into a different world.

It's recently been feeling like late spring/early summer here in southern California after some heavy rains like a week or two ago. Temperatures will be as high as 81F/27C next week. Warmest January in quite a few years over here. Would be nice to have a little bit more cooler weather here.

 Wednesday is gonna SUCK !!!

Yeah that right there is the number one thing I'm not looking forward to. My entire vacation will be far below freezing, so this snow
is not going anywhere for a while.

 I got a foot with drifts closer to 2' !! The snowblower was NOT happy ! Not supposed to warm up for at least a week !

I personally wouldn't call it severe(that term I reserve for summer & thunderstorms), but....Got a fairly short lived but heavy snowstorm here this afternoon, its tapered off to just light snow now. All in all got maybe an inch or 2 out of it, but at its height it looked kinda like a blizzard.
Temp is supposed to get below zero tonight (lows the past couple nights have been single digits & we've gotten little bits of snow)

Tomorrow its supposed to get above freezing for the first time since friday. .lol.

Pretty much snowed the entire day in Southern Ontario...This storm might have surpassed the infamous storm in 1999 when Toronto had to call in the military for support.