I don't think I quite agree with that.

Virtually all offices I've worked in, the bathrooms have been less than ideally used by colleagues. The people you'd class as 'commons' may not be having public sex, shooting up drugs, but many can be dirty and/or selfish. And this is in an office where cleaners regularly clean the facilities (I'd hazard more frequently than public toilets are cleaned). There's always be pee on the floor, pee on the seat, etc etc.