It’s a lot of the aesthetic. There’s no shortage of posts from people outside the punk/metal scene that point out despite the aggressive and “bad boy” appearance they find most to be nice, friendly, decent people. That’s not to say that everyone looks like that is, we’ve got toxic people, tourists, and cosplayers who steal the look but don’t adopt the ethos, but both scenes gatekeep the right way by screening out the assholes and letting them know such behavior is unacceptable and unwelcome. Battlejackets covered in studs and patches look tuff when finished, but it’s a lot less “tuff” when you see behind the scenes and realize there’s a community discussing stitching techniques, pro-tips on how to get your studs straight, and there’s a bunch of mohawked crusties splitting a pizza and a rack while having group sewing night.