The physicality of the job can be wearing.
Each store has many full-timers, at different management levels, and a few can be total asses - those usually don't last long or are moved out of the store.
The full-timers also gossip amongst themselves about the hourly workers - often spreading misinformation that effects reviews and raises. Once, my reviewer had a completely wrong idea about who I was and my attitude about my job, based on a small off-hand comment from his co-worker. That reviewer was wrong for assuming so much about something so important without asking me about it beforehand.
There are some long-time crewmembers that should have quit or been fired years ago because of their horrid work attitudes or plain anti-social behavior, but continue to keep their jobs because management seems to only fire someone if they steal (even the smallest of items).