I can imagine how much pressure they must be under to outperform their coworkers especially if they are cutting hours, but that is never an excuse of unethical behavior. Had he not pulled the "forced upgrade" thing, I would have happily bought the prepaid fuel and he would have had some extra brownie points and I'd probably have had a great experience, but as it stands, I feel my experience was pretty poor.
I usually rent with Hertz and I've never felt high pressure sales tactics there. I wonder if it's just company culture?