Because it's a nerdy genre of music, and trannies are just autistic nerds at the end of the day. Also explains why troons are so prevalent in other interests and spaces that are very appealing to nerds/autists, like programming, speedrunning, TTRPGs, Wikia fandoms, esoteric music, and various Internet phenomena that only turbo-autists would ever take interest in (ie Roleplaying, Neocities, YouTube Poop, etc).