Focusing on young adults and children is the only real way to make their readership grow. The average comics fan is older at this point, and like it or not, set in their ways. Having titles geared towards younger audiences is a great idea in my opinion. It’s a good way to promote literacy and get kids and young adults excited about the comics as a medium again.
That said, I don’t think every title should be geared toward children or young adults. Titles geared toward a mature audience will always have their place, as long as they are clearly labeled as such. Perhaps keeping up with the ratings system, and even promoting it, can help customers and families make informed choices as to what may or may not be appropriate for young readers based on their maturity level.
Childrens and Young Adult titles could be marketed toward Scholastic and local stores such as big box retailers and school bookfairs. More mature titles could still stay the domain of online stores and local comic-shops (which younger readers are less likely to frequent) It might mean a different approach, but that doesn’t necessarily mean it can’t work as well if not better than before.
I mean for example:
A young adult series of graphic novels, or even simply regular novels based around the new Stargirl series and it’s particular mythology. I think there would be a audience for it, particularly among young female viewers, who gobble up fanfic like candy.