"Either way, can any student think this is proper for school?"
It seems that many of these kids have never been taught that the concept of propriety has validity.
Insofar as they are aware of it, they seem to think it a wrongful attempt to stifle their self-expression, or some such garbage.
When they all look like safe variations of the same thing, I'd day it's more an effort to NOT stand out through real self-exression, but rather to merely "blend".