In my experience and speaking with transphobes I think it’s caused by our current culture of trying to force people to accept them.

Most people in my experience are happy not knowing or ignoring signs that someone is trans or gay. However when you start bringing it up in casual conversation or being overtly flamboyant for lack of a better term people start giving push back on it. I would compare it to the vegan stereotype. No one cares you’re vegan but when you constantly bring it up or try to make every conversation about you being vegan people get annoyed.

We as a society need to accept that racists and transphobes won’t change. You can’t force them to accept anything.