Maybe we always were, but back in the day nobody was getting theirs published. I can think of one very talented Sherlockian friend who got one novel published, and wrote a second one, but that second one only got read by a couple folks on individual copied sheets of the typescript because nobody was publishing pastiches at the time. And another friend who worked hard to complete an entire novel about Mrs. Hudson that the world never saw. The gateways to being published were much harder to get through twenty or thirty years ago.
But now every Sherlock Holmes fan has to try their hand at writing a tale of Sherlock Holmes and John H. Watson. The thing we never realize when that impulse first strikes us, however, is that those classic stories we love so much weren't really about Sherlock Holmes and John Watson.
They were about Grant Munro, Violet Hunter, Thorneycroft Huxtable . . . all of those colorful individuals, either at the front of the story, as clients, or at the back of the story as a criminal or victim, like Eugenia Ronder. Sherlock Holmes and Doctor Watson are really just there to help them tell their story.
We always get more of Holmes and Watson in the novels, because the form itself demands more content, and Holmes talking about his methods or Watson romancing the client adds more content, but the story there is still of Henry Baskerville or Mary Morstan, their lives, their issues. Sherlock Holmes is really a side character in their story.
One can nit-pick pastiches to death with rules and injunctions about Victorian details or not bringing in celebrities, but a good Sherlock Holmes mystery lives or dies on the strength of the characters who aren't Sherlock Holmes. In at least one commercial series of pastiches, I know the author created a character who sure seemed strong enough to move out and carry his own book, but the publisher demanded Sherlock Holmes stay in the stories to boost sales. But it was that original character, and his supporting cast, that made those books worth reading.
Holmes and Watson will always be the decorative icing on a mystery story cake, if you're not trying to write a story of their lives, which many do. It can be a lovely, well-decorated Sherlock cake, but once you cut into it, once you get past Watson's warm Baker Street intro, that cake better be able to stand on its own. I know I've put down my metaphoric fork on a few story cakes once the icing got eaten.
That story within the Sherlock Holmes story will always be the big challenge, and it was Conan Doyle's secret super power. He wasn't just a great writer for creating Sherlock Holmes. He was a great writer for creating Kitty Winter, Nathan Garrideb, and Henry Baker, without whom, Holmes might have never risen as high in our esteem.
It would be an interesting challenge for Sherlockians to have a little beauty pageant of sorts where you don't write a pastiche, you don't write a word of Holmes and Watson, you just write up a character study of the ideal client or victim for a Sherlock Holmes story, and that person can have no relationship to any existing person from the Canon. They have to stand alone, even without us knowing what their mystery is about. And like the traditional beauty pageant, there would be different parts of the competition, like "Distinctive Physical Appearance," "Memorable Name," and "Stand-out Trait." How much do each of those make us want to hear their story?
For those of us that write, and would like to write a Sherlock Holmes mystery, those non-Sherlock stars of the show will always be the challenge, and one worth spending a little time working on.