When I was in school I thought it was a terrible rule, because I'm a hat person and I like to match them with outfits from time to time.
Here, I allow my students to wear them because they always wear them appropriately. They don't play with them during class. [I'm shocked myself.] In fact some of my active students are the ones with the hats. No one wears hoods in my class, but I never made a rule about those either.
On another note, if you don't like it, enforce it. Too bad if other teachers don't help you. They are a distraction right? So it's fine to be distracted in your class? To me that's a sign of your co-teachers/ workers being rude. I do take away knives, notes, books, homeworks, ect (usually middle school does this) and I don't care if the other teachers allow it. It's disrespectful not to listen to a teacher that has worked hard for you.