They wouldn't, the point is that if there's a dude in the washroom with me I used to be allowed to alert someone, be against it and have my privacy. Now if any dude wants to walk in and be a perv, I can't say anything because that dude can just shout transphobe. Same goes for changing rooms, these guys used to be flashers and unwelcome but now I'm not allowed to consent to wether I see a Willy or not. Sorry if that hurts but not everyone is ok with that, some people want safe spaces away from cocks and the males attached to them. Namely sexual assault survivors, and religious women, and other women who just aren't comfortable with that. Now if TRAs are insistent on going into spaces with members of the opposite sex, why not just stop having sex segregated bathrooms all together? Also what's the obsession with discrimination in the dating world? literally everyone gets discriminated against in some shape or form (too fat,too old,too brown,too ginger, tiny cock, not into straights).