Check out this meaty 1989 Comics Journal interview with Bill Watterson (found over at Longform):
WEST: In looking at Krazy Kat, do you draw any strength from what Herriman did in terms of the relationships of his characters?
WATTERSON: Krazy Kat is a completely unique strip. I think it’s the best comic strip ever drawn. Ultimately, though, it’s such a peculiar and idiosyncratic vision that it has little to say to me directly. I marvel at it because it’s beyond duplication. It’s like trying to paint a sunrise — you’re better off not even trying. Peanuts and Pogo have been inspirations, too, but these strips are much more down to earth, and are much closer to my own way of thinking, and have had much more direct influence. Even so, I try to keep the instances of blatant plagiarism to a minimum. Looking back, you’ll see that some of the old strips are one-gag formulas, endlessly varied. Krazy Kat revolves around the tossing of the brick. Little Nemo was always a dream, and you know the kid is going to wake up in a heap at the bottom of his bed in every single strip. I find Herriman a lot more interesting than McCay, but both are working within a very limited construct. It’s a very different approach to cartooning that what we do now. I would go insane working with limited formulas like theirs, but on the other hand, Herriman and McCay gave us something better than gags. Back then, the fun was in the getting there. The destination of each strip was the same, but every day you went there by a different road. Today, we want the strip over as soon as possible — “Just hand me the punch line, please.” The fewer panels, words, and drawings, the better: I think Pogo was the last of the enjoy-the-ride strips. It’s a shame. We’ve really lost what comics do best.
WEST: Can’t you still do that with the Sundays?
WATTERSON: The Sundays are frustrating — you have to waste the entire top third of the strip so that the panels can be dropped or reconfigured for certain-sized newspapers. This really limits what I can do. Krazy Kat had a whole page to itself, as did Nemo. Even so, there’s more flexibility on Sundays than in the daily strips. I’ve always tried to make the strip animated, even when the characters aren’t moving, with expressions or perspectives or some sort of exaggeration. There’s great potential for that which has yet to be fully mined.