Pretty much because ethnic communities are very conservative, they're stuck by traditional gender norms (you know, macho man and feminine woman), that being ethnic and gay/trans gets you killed or beaten in some countries or areas in the West like the hood or if you're Catholic and Hispanic: your parents might tolerate you in the slightest but that tolerance will fade away eventually. The only way an ethnic can be openly gay is if they have a white or Jewish partner (not saying that as a bad thing but that's from what I've heard from reading stories of such. To be fair, I think WMXM is less fetishized too like with WMXF imo).
What's weird is that some ethnics deny any of this trans and gay stuff while we got RuPaul, SaucySantana, Lil Nas X -all famous ethnics and gay/trans-. They forgot that homosexuality/transexuality is not an exclusive race thing. Back in high school for me, there was some gay black dude who was out, loud, and proud.