After reading I'm YA and I'm Okay, two things spring immediately to mind.
1. Meg Rosoff has no idea what she's talking about: Meg Rosoff, an American-born author who lives in London, said, “There isn’t an adult who’s going to trot into the children’s section to look for adult literature.”
Clearly Meg Rosoff hasn't met a lot of adults.
2. James Patterson claims his Maximum Ride books didn't sell as well as his adult books because "in this country we tend to pigeonhole things" and they were only shelved in the YA section. I hate to break it to him, but they didn't sell well because he's writing for the wrong audience. Generally readers of that sort of fantasy tend to be a little younger. Also, according to the kids we know who have read them, they're not that great. And honestly, what are we talking about here? They all made the NYT bestseller list. Isn't he already rolling around on cascading piles of cash?