I seriously don’t understand the logic behind not explaining what job people are getting themselves into, and being surprised people quit.

I started working in a new autoshop. At the interview they didn't tell me I'd be working on stuff like box trucks, ambulances, and many other fleet vehicles they have that come to them. We do tires on them as well. The tire with the rim for these vehicles feel like they weigh near 100 pounds. It's fine for me, because I weigh 220. But they've been hiring guys who weigh under 150. Some of them told me they only weigh 120. And no, they were not told these are the kind of vehicles they'd be working on. So some of these guys will just quit before they destroy their back. Management seriously doesn't get why. And I can't understand why they don't understand.