Really what it comes down to is what is acceptable for wearing at school (and also at work).
For schools they just want to avoid anything that is too racy (to the point that it causes problems). Mini Skirts in the 60s were a big deal to schools and many of them banned that particular fashion item.
But could you imagine someone wearing a mini skirt on casual Fridays in a serious workplace? No. Its just too obviously racy. So while mini-skirts may now be acceptable at schools, they're definitely not acceptable in the office.
Basically, if you think its too racy and ridiculous, you probably shouldn't wear it.
Kilts on men however... yes, please do. Need more of that! ;)
Just not on casual Fridays unless your office boss happens to be Scottish and owns a bagpipe factory.