Universal truth? I don't think so. I take excellent care of my video games. Interestingly, my brothers on the other hand, do not. Maybe it's just a guy thing?
I don't go to GameStop anymore. I found a local place called Game Insane that's a little better. I traded in a couple of DS games I wasn't playing anymore (and yes, the clerk did remark on their nice condition, yay me) and got enough store credit to get a used copy of FF13, with about nine bucks of store credit left over. And despite being used, the game was in its original case, complete with manual. I don't know if they refurb discs, but they cleaned mine before they gave it to me and gave me a month to return it if it didn't work. (Works great, though, so I didn't need to.) Admittedly, the selection was a bit smaller, but the quality seemed better and less expensive.
And yeah, retail does suck. But if you can't stay zen, you shouldn't work in one. Even when I get a rude customer, I still treat them as nicely as everyone else. Then I ***** about them later to fellow co-workers, and we usually end up swapping bad customer stories and having a laugh about it rather than building up rage, or whatever. And honestly, I rarely get rude customers. Clueless ones and tiring ones, yes, but I don't hold them any ill will, because I know that no one's perfect, myself included.