I assume letting people return games also inflates reviews. People who can return the game can just do that instead of striking back. If they can return the game, you didn't hurt them.

I know after I got scammed on a "game" whose only gameplay feature was waiting, step one was trying to return it and, when that wasn't allowed, step two was leaving as negative of a review as I could. (Currently listed as "Overall Most Helpful Review" ;D )