The character of Doctor Strange has been around for 50-odd years, but Batman he is not. The big question is can a hero who is so far removed from the typical suit/mask/secret identity mix catch on with mainstream audiences?
The history of Doctor Strange does not reflect a very successful publishing life. In the 1960's, the books Strange Tales and Doctor Strange sold fairly well as cult publications. Sales on college campuses among the counterculture set were strong due to (misplaced) perceptions of Doctor Strange being a nod to psychedelic contraband.
Doctor Strange's title was cancelled time and time again over the years even though many of the story arcs were downright excellent. As a supporting character, Doctor Strange has been used quite well. Carrying his own book has proven tough. Can he carry a movie?
Why wouldn't he? Superhero movies are almost like Beatlemania these days.
At this stage, pretty much every hero movie draws people into theaters unless it is exceptionally bad. Fantastic Four pulled in about $50 million despite being a disaster of epic proportions.
Maybe the time is right for a Doctor Strange movie right now. An "atypical" hero could end up being what audiences want. The hunger for more hero fare is out there, but there is probably a want for something different as well.