I think there should be white noise generators in public bathrooms.
I recently read an article about the new ultra mega jumbo airbus plane and how the flight crews didn't like it because it is quieter than most planes. During long flights the crews take a rest and the white noise from normal planes drowns out passenger noise and provides them privacy enough so that they can sleep.
Privacy in a bathroom is generally a good thing. A cheap way to add privacy to a space is to make it loud. White noise is the least offensive form of loud.
Therefore, adding white noise to public bathrooms is a good idea.