It's so fucking simple.
XX Chromosome Bathrooms
XY Chromosome Bathrooms
Of course, I'm assuming that people today know what a chromosome is.
This forum will call me a liberal pink faggot, while mainstream culture will call me a hateful bigot for this reasoned central position, but I'm perfectly fine with saying I don't care what's on your birth certificate or your chromosomal arrangement. If you get the surgery and can no longer piss in a urinal, then fine, you get to use the ladies' room. Sorry Caitlyn, wearing a dress & makeup doesn't physically make you a woman. Cut it off, and you can piss where you like.
I get that it can be MORE off-putting for a post-op tranny to piss in the men's room. I get the intent of the people all up in arms about it. But it so very obviously and clearly can be abused to give free range to perverts to wave their dick at nude women & girls.
I can't believe there hasn't already been a scurge of trolling high school kids "identifying" as girls so they can shower with their female classmates, if for no other reason than to prove a point. This is not a wild hypothetical. This already happened in Washington.