Typically, though i suppose not universally, bathrooms are constructed with various interior screenings specifically to retain privacy when the door is open. Someone, somewhere, had the brilliant realization that because doors open (and also because other people might be in the bathroom with you), they shouldnt be counted on to be the sole or even the main source of privacy.

Which is not to say that i understand the logic of taking it down to prevent vandalism, but if the bathroom was properly designed, then nothing should actually be exposed that shouldnt be.