Why are people such slobs in restaurants and public restrooms?

Surely they're not that way at home? We were in a restaurant yesterday and people had let their kids spill food and cookies all over the floor... then walk on them so that they were ground into the carpet. The beverage station was a mess too... and the bathrooms had paper towels all over the floor and toilets weren't flushed. What is the deal??? Grrrr!!!