would tell you that you are wrong, but I can see your point, But again those children are learning how to respect each other, also mostly trainers are teaching then how to use they skills in a right way (by right way i mean , never to hurt or kill other person only self defence situations, out of the ring ofc. but at the end of the fight you can se judge making them shake they hands which is good thing also) ... Also they are teaching them self control , that is needed for all of the sports like this... So yeah in the end there is a lot of good things coming from sports of any kind, but parents are those that have to teach they children right manners.