Personally, I get where they're coming from. I too was a metalhead and grunge fanatic who considered people who preferred pop and techno music a different species and a hostile one at that.

I'd since grown up, though, and found that, while it's good to belong to a community, "the others" wearing its trappings doesn't detract from it or the good memories and gatekeeping is just a petty thing to do IMO 🤷

Edit: fixed my spell check apparently thinking that gatekeeping is behavior typical of Tom Petty, since it capitalized the word 😄