Everybody has a different standard for what is considered "clean." I am a bit messy, but I know that if there's gross residue on my bathroom sink, I should clean it up. Some people take cleanliness a little too far and think they must do a complete, deep clean of their house every week, which is unnecessary unless you have little kids making a mess daily. While clean freaks walk among us, I think it's more common for people to be filthy without caring. There's definitely a problem with parents not teaching their kids how to clean correctly, and those kids become adults who have no idea how to live a sanitary life.
If there's one group of people who should know better regarding best cleaning practices, it's housekeepers. They are supposed to be the professionals in the deep cleaning game, and that is what makes this situation particularly egregious.
