Humans have always been slobs. Many native groups lived in an are until it was just nasty and then built a new village. Our pioneer ancestor's tossed their refuse out the back door, or if they were lucky enough to have a flowing river, directly into the drink
Where would archeology be if it wasn't for slobs?
Certainly not approving of littering, but am merely pointing out that it is nothing new.
As far as the pictures showing furniture, probably a result of ridicules' charges for disposal. My local transfer station wanted 20 bucks a piece for a twin size mattress and box spring. I brought them home and burned them. Most don't have that option, and many don't have the 40 bucks!