Yeah, I know how fun it can be. I'm just curious as to why a single continuity is so important to us as fans.
Well, “fun” is sometimes the best answer you can give. But I gather you feel that the quest for WC canon is taken a little too seriously; you question why it’s so important to some. You should ask yourself two other questions: “Why are a number of physicists so intent on resolving the “conflict” between relativity and quantum mechanics?” and “Why was Isaac Asimov (of all people) so interested in contributing to Sherlock Holmes lore?”
The first comprises a dedicated career, while the second obviously involves a less than common pastime, but both could justly be confronted with the question of “importance”. What is the point, really? What good does it do (beyond inspiring Woody Allen) to know that one day, so to speak, the other six dimensions–based on string theory, which is often criticized as being untestable anyway–will likely “unravel” and destroy the universe as we know it, not to mention all life? And what purpose is served (beyond sheer presumption) in trying to “flesh out” Professor Moriarty more than his creator Conan Doyle cared to?
Look, the simplest answer in all cases is that we’re hardwired to do it. It’s what brains, and in particular our brains, do. Put in a more humanist way, we have a natural yearning to understand “us” and our “place” in the proverbial world. (Experiments in memory and left versus right brain activity strongly support that thesis. Some so-called neuro-philosophers would argue that’s the sole purpose of consciousness itself. Art and culture are then also offshoots, if you will.) And whether serious or frivolous, art and specifically drama (and the same goes for science) usually depict life with a limited, and thus more manageable, set of variables to ponder.
And ponder we do. I certainly can’t speak for Asimov; his motive in writing a story about the “early” Moriarty may have been only social (looking to join a formal club that included the likes of Tom Wolfe). But you can read his story as toying with how a scientific, or perhaps purely materialist, bent of mind can tilt towards evil. And a variation of that issue is clearly what interests any number of us in Tolwyn. Our attraction to Blair is equally easy to understand. But for us to make sense of them (to “get out of them” something of value to each of us), or of any of the other WC characters (including the human condition in general in the 27th century and later), the context has to make some sense too. And so yes, many of us are driven to “mend” inconsistencies in the storyline. (By the way, in that regard, I couldn’t disagree more with Haesslich’s reference to Blair and Jazz; I find Blair’s “recollection” wonderfully human.)
Of course we don’t devote such intense (or even minimal) interest to every bit of fiction (let alone fact) we come across. Whose brain could afford to? And so I guess that brings me back to each person’s measure of “fun” (and maybe, therefore, its biological function). Perhaps someone here will feel driven to choose cognitive science as a career, investigate the matter further, and report back as soon as possible.