Because there's maybe 0.01% of the population with transgender mental disorder. In the USA that a grand total of 30,000 people in the entire country. You could go your whole life and never meet one, outside of San Francisco.
The U.S. Justice Department says in a court filing that transgender students must be allowed to use the restroom that corresponds with their gender identity.
The department says in a statement of interest filed Monday that failure to do so amounts to sex discrimination under Title IX of the U.S. Education Amendments of 1972. The document is in response to a federal lawsuit filed against the Gloucester County School Board by a 16-year-old transgender student who wants to be allowed to use the boys' restroom.
Its a good time to be in the bathroom fixture business if you're a DemocRat.