After reading thread after thread on various boards complaining about the attitudes of cabin crews, I felt compelled to ask the title question. I am most emphatically
NOT trying to start a flame war, nor am I trying to denigrate the vast majority of top-flight (pun intended

) cabin crew members who fly us around the world. This is a serious question about that peculiar minority who seem to have checked out of their jobs.
I'm following up on the various complaints I've read, particularly in an increasingly difficult flying environment, about how cabin crews treat passengers. I'm especially interested in
why service differs so much from one crew to another, one airline to another. I realize that safety is their number one concern and that they train accordingly, but as the public face of the airline (along with the GAs), why do some crew members act like they just don't give a $#!%?
Is it the passengers they have to deal with? The schedules they work? Their gutted paychecks? Or are they just stuck in jobs they hate?