Well, maybe I was just in the wrong business, but no one in the retail grocery industry (that I ever met, anyway) gives a flying F. Burn out one manager, there'll be another bright young thing to replace him. Most of my adult students express, at one point or another, something similar about their experiences with their own jobs. Maybe there are businesses out there that genuinely care about the people they employ, but the vast majority of businesspeople I've ever met do not care about anything more than their own paychecks.
I agree that treating people like garbage and making them work long hours leads to poor performance. Most of the businesspeople I've ever met look at that and say "so what?" There's always a fresh crop of people eager to be put through the ringer, and as long as that's the only game in town--until basically everyone is able to get jobs where they won't be treated that way, people will put up with it, because the alternative is to starve. We've seen what happens when government doesn't regulate businesses, and it's a freakin' nightmare.