I just saw this, I can't believe people are actually defending the use of this kick in competition, if they are going to allow strikes to the knee, they might aswell allow strikes to the throat, and eye jabs to see if you can cut your opponent's cornea,combat sport is supposed to be a way to fight without getting seriously injured or without inflicting serious injury to someone else, that's why rules exist in competition. But if they are gonna go this far, they might aswell do no rules and just put in on television for everybody to see.
I think there's a lot to learn from this. Even in competition there's people who want to hurt you real bad, despite the fact that it's supposed to be a sport. so why think about rules. Just think about having no limits. And train with no limits on your mind.