This is like taking a right off the person, Effecting the person's full life until death. That is unfair! A hairstyle is extremely important for a person's life and if it is ruined, Then unfortunately it will stay like that forever, Not unless you are bold. People have the right to take control of their own body, Not to annoy others.
If students are forced to have a specific haircut, students are not allowed to be themselves, in a way. Your haircut is a display of who you are. It's insane to think that you get sanctions for being who you are. Sanctions for a ridiculous haircut is understandable, but having specific haircuts is not. "Improper" is an opinion. And you cannot shove opinions down on everyone.