[Hylas]

Some schools don't let you choose much about which clothes to wear. And apart from the skirts thing (that was only an example), I say that school is a quite bad experience for some people, also without adding to it the uniforms problem. Everyone has a certain specific personality and should be free to express himself also with the way of dressing. Some people feel better if they have the opportunity to be different from others.

Showing your uniqueness doesn't mean you're not equal to others, it means you have the right to be different and to show others you're not an anonymous clone among the others. This can sound stupid, but having a personal style is a good way to start, at least for some people.
Equality has to be expressed in other ways, not thanks to school uniforms.