You can't trust people to vote on stuff responsibly! I mean, AAMPAS voted for "A Beautiful Mind" over "Fellowship of the Ring"!
People might decide to vote for the lamer because they think it's funny. In some kind of organized competition, voting will probably be the best way to go, but when you're dealing with the Internet mob, you should not give them any deciding powers lest they pervert them! And then there's the fact that the voting will probably delay the game a bit between matches.
Anyways, we probably should add voting, but as an option.