Honestly, that seems less of a testament to consumers' gullibility than it is proof of Disney's successful branding as a "family oriented" studio.
However, the Mouse can afford to take a "live and let live" stance with Pulp Fiction, Dogma, etc. because the content is inherently produced for adult audiences, to begin with. (Which is why I actually expect *more* support for the MAX and Icon lines, with the influx of "Disney money", ironically.)
My personal concern about Runaways stems from the fact that it's a book that's both about and for teenagers, primarily. That might be in direct conflict with the Disney brand identity, especially when the younger end of its target readership may conceivably be preteens who are starting to outgrow High School Musical, and are looking for more 'serious' fare. I could imagine the brand managers not wanting their market "transitioning" into a series that features pansexual aliens and sexually active Goth girls. (And yes, I *know* it's handled in a nuanced, human manner... That's why I still read it. But I'm not sure if I trust Disney's image police to see things the same way.)