(Aside from the obvious, that is.)
I recently finished reading a book about fandom, Textual Poachers by Henry Jenkins. It was published in 1992. It examines various aspects of the fan community, and in a section about how fans interpret material by re-watching it, I found this choice quote:
“Each time I see [Star Wars], a new level or idea about something in it shows itself. [Part of the fun is] piecing together from the few clues what the Old Republic was actually like, who the Jedi were, what Han’s background was, … what the Clone Wars were[.]” (Roberta Brown qtd. in Jenkins 1992, 73)
That’s the entire fan controversy in a nutshell, right there. Fans watched the original movies and came up with their own theories about the background material. By keeping the background in a liminal, undefined state, it was alive and exciting. By solidifying his own version of the past in the form of the prequels, George Lucas effectively killed the fans’ grounds for speculation. That, more than the shortcomings of the films themselves, is what inspired fans’ ire.
Bonus: A moral for writers of fiction. Gaps in stories are not necessarily meant to be filled. Interesting background is often more exciting when it’s undefined; when we see the trappings but don’t necessarily know what’s behind them. This is a rocky road to tread (background still has to at least appear to have a reason to exist, you can’t just make things up at random), but it pays to remember that some things are better off unexplained. Bill Watterson never defined what “The Noodle Incident” was, and you can bet if he had, it wouldn’t be as absurd as you imagined it.