Manga is also read by far, far, far more people than American comics. Comics in Japan are as common as Newspapers are here in the US.
DC makes superhero comics and that's it. They do have some other non-hero lines, but DC is all about Batman, Superman and the rest. These are all suppose to be comics for all ages, but that is no longer the case.
Of course, it is NOT Johns fault 100%, clearly he is just following the current threads, trust me, if DC didn't want their comics to be gore encrusted mindless crapfests, then the editors would never ever let them get made in the 1st place.
There are other types of comics in the US besides Superheroes!!! You know some of which FAR OUTSELL any superhero comic being made today.
Real mature comic book do not feature superheroes.
I mean these of course:
http://www.time.com/time/2005/100books/0,24459,graphic_novels,00.htmlNeither do real children's comics! Children's picture books and things like Harry Potter has taken over that segment.