Why do the rules favor certain techniques? Mr. John Zimmer stirs things up at My Self-Defense Blog with a post about how the rules have changed in open martial arts tournament sparring. See Karate Tournament Rules; How Many Points for a Kick?! for a very nice discussion in the comments with Zimmer, myself, and Sensei Matt Klein.
The gist of the matter is that there is a distortion in competition so that there either a purity of style, or a desired outcome. In the case of style, TKD tourneys favor high kicking above all else, and de-emphasize punching, especially to the face, while (as I mentioned in the comments at the post) the UFC started giving financial incentives to the fighters to finish a fight with a KO, as opposed to a decision or submission. Why?
Check out My Self-Defense Blog to find out!