If an answer is wrong, users might want to downvote it, but don't want to lose two points. Then a wrong answer could stay because people who know it's wrong don't want to lose points. Maybe it shouldn't cost 2 points to downvote something.
Sorry but that's probably not going to happen. It's there to discourage people from voting down posts for the hell of it. 2 points is basically nothing, I'm sure people would be willing to spare them to contribute to the question.