Yes. I’m older and remember this as a kid. Very young kid.

Us kids probably keyed into this more, taking to the heart, as they say. The older generation I imagine rolled their eyes. Their attitude toward litter was “trashy” to be sure. I can recall opening the package of some toy in the backseat of a car on family trip. I asked what should do w the packaging. “Oh just toss it out the window,” was the reply. So I did. Can’t remember the toy but remember the cardboard fling out the window.
And cigarettes.
To people who smoked, the whole world was an ash tray.

Also as kids, we were closer the litter. Literally. Walking home from school we could see it all at our feet. So the subject of litter was relevant.