Unfortunately most cis liberals don't explore strange new gender identities, and they don't seek out new life or new presentations. So their only experience with the strange is from transphobic jokes. You see, transphobes seek us out. They want to meet us, so they can make fun of us and use us in propaganda before we get around to representing ourselves.

So a liberal sees a dronegender person, and their thought process is "I've never seen that in the queer spaces I've never been to, but I've definitely seen that in 4chan threads attacking trans people. This gender identity must be an attack on trans people."