This is one of those things that only makes sense in writing. Reality is that it's no different than if you got in a brawl at a bar, restaurant, etc. You don't get to come back inside like nothing happened. Your tab gets closed and you are kicked out. Not having the rule simply leads to more violence. It's the same reason why self defense castle doctrine states are linked to having MORE murders than not, and these are adult brains. You are suggesting that you have 14 year old brains deciding whether or not they are justified in commiting violence, with the idea they can argue along with their 50 year parent with also the same brain as a 14 year old that they shouldn't receive any consequences. For every justified self defense action will be multiple more needless violence.