How is it that many schools in Europe and elsewhere get by perfectly well without imposing a school uniform? I don't think French, Dutch, Swedish, Norwegian and German, etc., schoolchildren are any more undisciplined, unmotivated or ill-educated than our own.
I can see that there is perhaps a case for having a very loose dress code for practical and health and safety reasons - e.g. no high heels, dangly earrings, etc., but otherwise I do think a lot of unnecessary conflict is caused by the insistence on sticking to some very rigid rules.
Can it be assumed that improvements in a school are solely down to the introduction of a strict uniform policy rather than the "other measures" that are also introduced? Some schools that have introduced a more rigid school uniform policy have not improved so it may be that the issue of uniforms is fairly superfluous.