Often it’s fear. They think if they’re a perfect, respectable minority, they can appeal to the kindness of queerphobes and win rights through sympathy. Sometimes it’s even trauma. Gay guy is used to being called a girl for his gayness, and is triggered to see a trans woman willingly taking that on. Or trans person is used to hearing helicopter copypastas and thinks otherkin are conservative trolls. In both cases, they’re used to being attacked with the idea of more marginalised queers, and think they can switch sides to the oppressor’s corner if they disavow the smaller minority