"But they…"
Okay, and you don't understand how transphobia is not just about you? That it contributes to dehumanization of others outside of the scope of your disagreement?
That dehumanizing contributes to a _culture_ of dehumanization that is currently a very, very real threat to many of us? That there are overarching _systemic_ and _societal_ issues at play outside of your own feelings?
Go challenge them to a duel or whatever. Don't misgender them.