Here’s a gem of an observation from Welty’s On Writing:

The plot is the Why.  Why? is asked and replied to at various depths; the fishes in the sea are bigger the deeper we go.  To learn that character is a more awe-inspiring fish and (in a short story, though not, I think in a novel) one some degrees deeper down than situation, we have only to read Chekhov.

That character is a bigger fish in the sea of writing than plot, many writers have said, but few have said it as eloquently.  I have to admit as well that I’m curious about her distinction of the novel and the short story.  I’d say character is just as important to the novel as the short story, but I can see her point that plot matter more in the novel.  Otherwise, you’d end up with a sequence of chapter episodes rather than a novel as a whole.