A shame you plan not to reply, because you might help me understand why people believe that acknowledging a defect somehow mitigates its existence. Why not just be less pompous, after all?
I suppose I ought to put that in a full-fledged article & try to earn some pocket change. The short version is that, like Arthur Conan Doyle, he took hints & ideas from other writers—Chambers, Machen, Dunsany, Bierce—& formed them into a reasonably coherent subgenre: cosmic horror. Which I quite enjoy, when it's done well.
What more is to be said?
This isn't really a conversation about taste, because we've already established, in any language, its primacy in guiding our appreciation of a work. Rather the issue is to what degree, if any, the author's personal failings invade his work. Is Der Ring des Niebelungen, by comparison, an inferior opera because Wagner was such an all around schmuck, and because Hitler claimed that to understand National Socialism one had to understand Wagner?