1st: he brought superheroes into the realm of adult literature with Miracleman. Continued with Watchmen. You can argue Tony Stark aint all that complex, Marvel movies are formulaic, but there's certainly enough fun there to not be just for kids.
2nd: the same argument can be made for any eacapism. James Bond, Game of Thrones, Star Wars... all pathetic kids stuff.
3rd: diversity has been forefront on many standard comics and is almost always a good thing for every audience. We've had a black partner in Batman, Miles Morales, concentration on the X-women, a teen Muslim superhero, and it will continue. To say none of this has moved the medium an inch from all-white male power fantasies is pretty disingenuous.
Finally, this is a guy who still throws rape into almost everything, boom... adult!
Im so tired of Moore looking down on people enjoying a good guy vs bad guy story with fantastic elements. Comic books are the new Greek mythology, we enjoy stories with heroism in non- real life settings. Except we're now aware thats exactly what they are, fun stories that represent heroic ideals. Like All-Star Superman, he's a mythical representation of the best humans can be, what is juvenile about that?