The tournament master makes it clear that the tournaments are meant to be using non-lethal weaponry, but instead of using the practice weapons, tournaments currently use normal weapons and their associated blood-splatters. Since the practice weapons (and their associated lack of blood) are already in the game, it seems a rational thing to change tournaments to use these. Although I'm not sure what's up with the blue-tinted dust that replaces blood sprays when someone is hit with the practice weapons; I could do without that, myself.