I've always thought it was weird that if an extra point is blocked, the ball is dead; the defense is not allowed to advance the ball. I think if they block the attempt and manage to advance it to the other endzone, they should be awarded the 1 point. Same thing with a 2-point conversion. If the defense intercepts or recovers a fumble and advances it to the other endzone, they should get the 2 points. To me this only makes sense. During other times of play, it's always possible for either the offense or the defense to score.