I think he had a quite sort of ambiguous relationship to Holmes. It made him rich, it made him famous, but as often the case with these things, a writer can turn against his or her most successful creation; hence, he killed him off (in 'The Adventure of the Final Problem') and brought him back by popular request. And, of course, people did sort of confuse them and assume if he could invent these complicated mysteries, then he could also solve them.