They can, it really is hit and miss. I used to see them come back burnt out w/in 6 months all the time. I usually put it up to a customer that didn't know what they were doing (touching the bulb, throwing it around), but it was somewhat often.
I have some PIAA bulbs in my truck that have been there for well over a year now. Mind you I don't drive the thing that often, but none the less, I've been quite happy.
I have used the PIAAs and Silverstars with very good results (4 years! with DRL's off). I am actually running one of each right now to compare. The Silverstars are actually a little brighter than the PIAAs but either is good.