Many people do inded argue that Harry Potter is not a children's book, which is what inspired me to write this article rather than having the same conversation a thousand times on Twitter.

I've found that the lessons in children's books are useful for children, while literature for adults conveys deeper lessons that are applicable to the lives of adults.

At any rate, Neil Gaiman is the artist most blatantly ripped off by JK Rowling, both in the general tone of her books and the specific plot and main character of Gaiman's The Books of Magic, so he's got a right to whatever opinions he might hold about JK Rowling. https://en.wikipedia.org/wiki/The_Books_of_Magic