The law is not based on your personal experience with gay and transgender people -- or your belief that transgender females will not seek to shower in wide open shower rooms  or use women locker rooms.  The law applies whether the transgender population is  .4 percent, 4 percent, or 40 percent of the population.  It does not matter one whit if the transgender person has no resemblance to the sex they identify with.  It only matters what sex the transgenders identifies with in their mind.  What I wrote is not unnecessary rhetoric, it is the law.