I know there's no such word as 'adultised' - but it matches what I have in mind. When I was a kid, I read DC comics (for some reason, Marvel didn't seem to arrive in Rochdale til after I grew out of them). I enjoyed Superman, but Batman was far better. This was because an important part of reading these comics was role play. It was hard to emulate Superman without, for instance, being able to fly. But, trained though he was, Batman was just human, and so far easier to feature in pretend play. And most important of all, he had his utility belt.
Oh, that utility belt. (I was spurred into writing this, by the way, after passing a police officer as I came out of Temple Meads station, thinking that her gadget-bedecked high vis jacket looked like a utility belt.) How I wanted a utility belt. And, inevitably I made one of sorts, though it didn't carry quite as impressive a collection of items as did Batman's own.
I know the move of comic books to shades of grey in the spread of 'graphic novels' (they really aren't novels, guys, I'm sorry) has made superheroes more attractive to an adult audience. And though I share Stephen Fry's doubts about the genre having such a hold on the box office, I do enjoy some of the modern reboots. But what a loss. There is no way that the modern Batman is a sensible role play option for children. The utility belt now seems far too tame for Batman writers. So while I have nothing against 'graphic novels' per se (apart from the name), I am very sad at the way they have deprived today's young people of an exciting part of their innocence.