Lynnfredricks, I don't know. I like to think that Lovecraft didn't continue to bind himself to "facts" established in earlier stories, but would have felt free to strike out in new directions had he lived. His was not a "Tolkienian" imagination. It was more like Lord Dunsany's, I suspect. I don't think anyone tries very hard to work up a "body of lore" drawn from Dunsany's stories. Tolkien would, it seems, wait upon his imagination to establish various elements of Middle-earth, and those things, once established, could become the starting places for further "discoveries." This really worked well for Tolkien. It was as if the established things freed his imagination to explore further. He gets straight that Trotter is Strider and isn't a hobbit but rather a descendant of Numenorean kings. That opens up a lot! I don't see much of that happening in Lovecraft. His late story "The Haunter of the Dark" is fun to read, but its "Cthulhu Mythos" trappings feel to me pretty much like use of "stock on hand." The fact that Lovecraft encouraged other writers to "play" with "Yog-Sothothery" is not Tolkienian. Tolkien was very concerned about inner consistency between The Hobbit, The Lord of the Rings, Akallabeth, Quenta Silmarillion, etc. Again, that was how his imagination worked, and the results are wonderful. I think the "Cthulhu Mythos" was, like Dunsany's stories, largely a plaything for the author, and perhaps one he could set aside. Tolkien is now dead, and those who are acquainted with his work can see directions that he could have gone if his energies had remained strong, etc. into late old age. But really what worthwhile directions were left for Lovecraft with "Yog-Sothothery"? It seems rather that he left some tropes that writers with inferior imaginations (Derleth, Bloch, Lumley) could reuse, and add to but not in any really very significant ways. You can accumulate further entities, monstrous races, hideous subterranean realms, undiscovered planets, and, notoriously, forbidden books.... but why would a serious author bother? I think one's enjoyment of such works is that of walking a familiar path, as I might enjoy the later Sherlock Holmes stories by Arthur Conan Doyle. That's probably the main justification: write them for amusement. Lovecraft himself sometimes just wanted to amuse the reader ("Haunter"), of course. He clearly knew that the "Mythos" could do that. Likewise that others might enjoy writing "Lovecraft-style" stories. He himself had enjoyed writing in the Dunsany manner.
