What is it about public washrooms?

Why are people so dirty and disgusting in public washrooms? The washroom at my work is cleaned every evening and I feel really bad for the person who has to clean it. Every morning it starts off clean but before the day is over it looks like it was over run by farm animals. It’s to the point that I avoid the washrooms in the building when I can. I don’t know if its one person making the mess or multiple people through out the day but who ever it is I wonder if that’s how they are in there own homes? If so I never want to visit and I hope they never visit me! It’s disgraceful! I would go into more detail but it is just too disgusting.