The people who say "it's to make you interact with normal people!" miss a key point. In the real world, you meet a person, and if they treat you like shit, you walk away. If they physically assault you in the workplace, you can report them to HR, and there's a good chance you'll never have to see them again. In school, you get told you need to have empathy for their propensity to beat you, get subtly or not-so-subtly victim blamed, and you still have to interact with them for at least a year, and maybe years.

Exit is probably the most powerful strategy to dealing with certain kinds of situations, and schools deny you that.