For instance, Shonen is not a genre in itself but rather a target demographic. You can't say that Death Note has anything in similar with HunterxHunter.
However, Superman, Batman and Spiderman are all superheroes stories. Even if they have science fiction or fantasy elements within those stories the main angle is not on the science fiction or fantasy elements.
Again this is not meant to bash Western Comics but rather to pose a self-critical question. If we have self-criticism then the comic industry would reflourish and maybe start moving away from the Superhero genre into more exciting territory.