Allowed? Where do I say he is or isn’t allowed? You must be trolling to so poorly represent what I’m saying.
He can wear anything he wants. So can you. So can anyone.
If he wants to, and for all I care, he can dress up like a clown. Or dress up like a jester. Or he could wear Gucci or Prada. Or wear steampunk leather outfits like he is in the world of mad max. Or he could go clean cut preppy. He can wear a fedora and a trilby on top of one another.
But, by personal choice and temperament, he wants to dress as he dresses. It just so happens that his personal preference aligns with a particular trope. A particularly uncool trope in popular culture.
I’m pointing out that alignment. I am not making him dress that way and I am not forcing culture to judge him.
I'm not buying this alternative reality where I'm trolling by pushing back on mocking someone's choice of a hat that is one of a limited number of common hat styles.
But why should he not be allowed to wear one? Again, you're policing. It's a discriminatory dick move.