My PG private school had uniforms, even for hairstyles. And the second one had a really strict dress code (no denim, no shirts with writing or logos, etc.) Compulsory uniforms are really only good for elementary to maybe middle school. Financially they don't offer that much advantage either - school uniform brands don't run cheap, as I remember it, especially not when you have to purchase multiple sets and you still have to buy casual clothes for athletic wear and weekends.
People also tend to assume that having compulsory school uniforms will remove a lot of the social pressure that comes of people buying their own individual clothes - cattiness over brands of jeans, shirts, dresses, shoes, etc, the theory being that no one can make fun of the clothes your kid is wearing if they're wearing the same thing. Well, that's not true. Trust me, kids will still have ways to "show up" others, between purses, hairstyles, shoes, jewelry, athletic gear, makeup. You will never remove teasing over personal attire just by making everyone wear the same ugly plaid skirt.
Also, by the time they get to middle school, kids are developing their own identities and choosing their friends based on those identities and personalities. Clothing and personal garments are the easiest way for kids to express themsleves in the public school system. And not by "bad" things like the logo on your polo (Hollister? Aber-crummy and B!tch? - I'm hardly a fan of brand-names that plaster themselves all over the shirts they sell), but things like the rock band represented on your t-shirt, the bright colors of your shoes, the crazy style of your haircut. I'm not trying to be all "omg expression," because I don't recall anyone ever wearing anything groundbreaking or revolutionizing to school, haha, but heck, at least we had the option to wear something for the college we liked, or for our favorite sports team, or our favorite rock band. One's personality shouldn't be based on material things like clothes, but clothing is one of the easiest ways for teens to express personality or things they like.
Plus, I paid for all my school clothes starting around freshman year of high school with money from my jobs, and fiscal responsiblity is a much easier lesson to learn when your hard earned and well-saved cash is being put to use for some goodies you're actually excited about wearing, instead of another pair of gray knee socks.
Not saying it hasn't worked for some schools, or for schools trying to maintain a standard of modesty (Riverdale Baptist, Queen Anne, Elizabeth Seton), but the fact is it would be pretty impossible to switch public schools to compulsory uniforms all of a sudden when the norm has been to wear what you like (within the standards of the dress codes) for so long.
Yeah, I hate it too when kids come to school with ratty hair, sloppy t-shirts, or pajamas, and it looks terrible. And I, too, would like it a lot more if students looked a bit more polished. But compulsory uniforms are not the way to go, especially in a school system that the kids have no choice about attending (public school).
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