There were grassroots anti-littering campaigns all over the place back then, so it was an easy sentiment to tap into. It's really hard to convey how OK everyone used to be about littering.

If you've seen Anchorman there's a little bit where the news team are eating hotdogs and walking through a park. They come up to a trash can but throw their dogs on the ground before tipping the can over. Then they just walk away and there's no explanation. That was normal life until the 80s.

Every album before this sounds like late night bluesy dive bar music with a slumming guitarist and crappy singer.