All schools want Lemmings nothing more nothing less!
I like dress codes. I prefer not to have my daughters viewing lewd remarks on the backs of T-shirts in front of them in class.
Children in society do not have the same freedoms as adults. They cannot vote, in many states they cannot drive. They cannot be licensed to own firearms. They cannot serve in the military.
Adults in society have rules too, including dress codes. A nurse cannot show up for work in a sequined mini-skirt and six inch spiked heels. She ( or he) will be fired.
Adolescents are rebellious and like to test their limits. This young person learned that when you make decisions you deal with consequences. She may not miss that 1,000 dollars now ( assuming that mommy and daddy aren’t paying the bill) but she may when the newest i-phone comes out and she can’t buy one.