> Chronic litterbugs don't care, they're often low enough on the hierarchy of needs that this kind of morality isn't on their radar at all.

Don’t forget the deliberate litterbugs. There are plenty of people out there with a “for every bottle you pick up, I’ll litter three” attitude. Belligerence against anything seen as a public good is on the rise. I know someone who believes having a clean, trash-free neighborhood is a “liberal” thing. Blows my mind.