Of course CN is a classic, but almost the entire four sides around it - musically, lyrically and conceptually - came from Roger's brain. I don't think you can blame him for not wanting to spend much time on democracy at that point.
The same for Animals, the same for The Final Cut (which I like).
Don't get me wrong, I'm a huge DG fan, but he just didn't seem to be writing around then (or much since, for that matter).