I was typing up a direct reply to you when I saw the email about your reply pop up.
It isn't just books with cartoon illustrations. Think "Twilight" (ugh) and "Hunger Games", too. Even books like "The Fault in our Stars". I think they're mostly written for people 15 - 20, maybe. Though others certainly enjoy them.
Good lord. I put the first Harry Potter book down years ago as it was clearly a children's book I really should get to reading those I guess!
Angsty-teen books though!
Seriously. They are good books. I hate this division into YA and non YA. It's an enchanting story at any age.