"Rowling doesn't." (require thinking)
Agreed perhaps not on the same intellectual level as some authors but there are certainly numerous riddles, word games and other entertaining diversions either obvious or hidden in the text. These and the way one can obviously identify with many of the characters are just a couple of reason why the HP series so entertaining. I cannot see the comparison with Enid Blyton at all!
mcmoo (suitable chastened and creeping back in disgrace to his Isiah Berlin)