I just upvoted you. This drives me nuts. If you haven't experience a game first hand, then don't rate it. You know nothing about it until you've actually played it. Nothing. I have games I clearly think I won't like, and am sometimes pleasantly surprised by how much fun they are.

Another close pet-peeve is people that know they've played a crappy, poorly maintained version of a game and still somehow feel justified in rating the game. For example, Superman--everyone slams the game, and one of main reasons is that "the flippers aren't strong enough to hit the shot at the top". For crap's sake, that means the game is not playing at intended, so why rate the game poorly when you know it's a maintenance issue.