I find it interesting (well, actually, sad) that the author chose that picture for the image of a "public toilet", instead of, say, anything like here: https://www.google.com/search?tbm=isch&q=지하철+화장실

(The query says "subway restroom")

It's a classic failure of imagination. When you live your entire life using (or refusing to use) abysmally dirty public transit system, you kinda assume that it's a part of inevitable human nature. And then of course it stays unchanged, because everybody in the town knows it can't be helped so why waste precious budget on it?