Well, usually the company who holds the license to that project looks to hire new people for the position and not the same one over and over. Of course this happened with Mark Steven Johnson(Daredevil) but the reason why I think he got another chance at a superhero franchise(Ghost Rider) was because there was no sequel put into development for another Daredevil film. Think about it, basically every director of a superhero franchise sticks around to make sequels and then you never see them direct another film in the universe of Marvel comics. He may be asked to executive produce another Marvel project but that's about it, after that Sam Raimi would probably be out of the world of Marvel comic-books.
