The sad thing is that the managers are usually fucked over just as much. I've worked with managers working 70 hour weeks over the summer and holidays for $50k a year. Anytime somebody customer goes ballistic its up to the manager to solve it. If someone ODs in the toilet the manager has to call the cops and get them out. The chain I work at will promote people to manager positions, if they're willing to move across the state, and they better be comfortable with filling in at other stores should they be needed. If nightcrew is shortstaffed (they always are) then it's the manager's job to fill in. Being a manager is just as miserable unless you're a sick fuck who takes pride in making a salary that just barely pays the bills.

Edit: Oh, and is some policy not being followed to the letter because the teenager you're paying minimum wage doesn't care? Is some shelf empty because the warehouse didn't send you product? Corporate will chew your ass out and threaten to fire the manager without a second thought and then the manager has to do something that is gonna fuck up everything in the store for a week to please corporate.