It is just plain common sense, and common decency, that men do not belong in women's dressing rooms. Period. Not even men who pretend to be women, and not even men who are so desperate that they have their genitalia subjected to surgical mutilation for the sake of that pretense.
You have no valid argument to make against what is so obviously true, that you have nothing left but to accuse those who stand for decency of being bigots. It isn't going to work. Nobody is falling for that crap any more.