I'm not entirely sure of the logic of why somebody would be cleaner after paying 50 cents than otherwise. It seems like a move to keep away homeless people, but even then, it's not that hard to secure fifty cents and unless they have a timer going in there, which seems ill-advised, it wouldn't help either.

In any case, I've only ever seen them in outdoor latrines and rarely in public transportation hubs. They are definitely not the norm anywhere I've been.