This attitude of shared responsibility, taught from childhood, help to explain the difference between the cleanliness of subways and subway platforms in Japan, and in the US.
Yes and no. You have dirtyness in Japan everywhere too, but they just systematically clean a lot and very often. Public toilets can be cleaned like 10 times a day. This frequency is unseen in the US
source is my eyes. There are cleaning sheets in most public toilets and you can see how many rounds they have every day since they stamp it every time.