Lawsuit is the answer. Incidents that happen carry no civic responsibility, and the only way to now not get sued is to go fully unisex for NON EMPLOYEES. Employees, it gets a bit more complicated.
And every developer in the world would rather just pay a bit more extra to make the unisex spaces, than to deal with unknown amount of lawsuits later, easy way to derisk.
And I also to a point agree with you that this makes everyone less safe from men but hey, you guys keep cheering when laws that remove the safer way gets enacted because you are so focused on transgender people that you forget about the actual danger, which is cis het men responsible for almost all of those crimes.
Not like no one warned about it or anything, but blind bigotry does not care. Now watch further protections get eroded, all in the name of transphobia.