It's because they don't give a flying fuck about actually solving problems and only care about their optics. "Look I suspend everyone for fighting no matter what, I hate violence! Keep me as principal and I will continue to make sure there is never any violence again!" they say as bullets go flying because that one weird kid that's picked on isn't able to just cold cock the person bullying them.

It's the exact same mentality of conservatives with drugs or liberals with guns, where if we just make it illegal, then the problem is magically solved.