I get that someone should know that they are buying damaged goods, but these are used games from a rental service. It should be a given that there might be minor scratches on a disc. And I would certainly call scratches 'damage.'
I don't really have a problem with people talking about the chips though. It's the "ZOMG GameFly is the worst! All their games are chipped!" reactions that people have that irritate me.
You're buying a used game. If you don't want chips or pitting on your disc, that's okay. Send it back. But if you are expecting a flawless perfect disc, go buy it new.
I wonder what some of the people who are very vocal about it would say after buying some used games from GameStop...