Well, I believe NCAA said it had to be like 4x12 - no more, no less (I believe too). Maybe NFHS followed suit.
Seems the last few years we've seen an increase of towels that were like flag football streamers (obviously serves no purpose).
Wearing a towel itself: I dont have a problem with. It's the wearing the towel as a 'fashion statement' is the issue.
There's a lot of "you cant wear this" in the rules which on 1 hand seems like a waste, BUT if it's not spelled out in the rules, chances are you will see someone wanting to wear it.
It's not great to play fashion police, but with all the nonsense you see players trying/wanting to wear, I'm glad in a way we have the fashion rules.