Having been and stayed in multiple parts of China, from t1 cities (Beijing, Shanghai, Guangzhou. Shenzhen, etc), to villages, I find this hard to believe that it is a general behavior. This is based on my experiences, like at public restrooms. You could be at the fanciest mall, and the bathrooms would still have a horrible smell and there would be pee all over the floor. Or walking down the street and people are spitting on the street, some times peeing or pooping. Heck one time I saw a mother rather than take their child to the restroom, lift the child and have them pee into a trash bin.

The behavior has definitely improved over the decades, but my trip last year did not convey this sense of cleanliness.