darklordoftech said:

I aabhor the very concept of fictional canon. It's all fiction.

Good point.

In Misery, Annie Wilkes wouldn't accept Paul Sheldon's first attempt at making a sequel. [There is that Lucas/Misery parody, but not what I have in mind.] Maybe all fans should be comfortable with rejecting material without worrying about offending canon.

To some extent, I think we confuse canon with copyright (not just the legal right, but the general belief that a creator is the only legitimate person to decide what exists in his/her fictional world).

Among the Oz books, there are ridiculous inconsistencies - even in just the books written by Baum. That Baum had the only true right to craft the world of Oz was undisputed, but his books do not lend themselves to lasting and consistent rules of how that world works. When later authors try to reconcile inconsistencies, it feels unnatural, trying to make the work fit a canonical ideal.

Back to Star Wars, I think of IV-VI as the only real canon because there was a creative integrity to them, like three chapters of the same book. But in the end, I think you're right, dlotech. Canon in fiction is not an absolute. It's a responsibility of a creator to try to maintain the fiction of canon.