They serve a purpose, and the Quaker in me thinks the best purpose they serve is to set a general standard and prevent a lot of the between-student problems generated by fashion and money. I also had a job that had a very strict dress code, probably the strictest in the country, and it never hurt me, in fact it reinforced my general fondness for dress codes... at work, of work is another story, with school being a similar case along with formal and traditional events. The same reason I'd frown at someone for not wearing a tux or dress to a prom makes me frown at people who don't show up to Halloween parties in a costume or would jeer a historical re-enactor for showing up to the Battle of Gettysburg wearing a kimono. But I think one can't say that one doesn't have much use for dress codes unless one is a casual nudist and even that's questionable.