How is maintaining public restrooms a "massive liability"? Surely its an inconvenience but massive liability seems a bit of a hyperbole.
Try hiring someone for a job where the job could sometimes be cleaning up bodily fluids and odors in a bathroom. Even the government deems it infeasible.
Or, think about how much someone would have to pay you to do that job.
You don't see how maintaining a bathroom where the worst of society engage in public sex, do drugs, and shit it up in general - is more of a liability than without those things happening?