Why is this boy so successful?

You know a children's book series is a success when it's written about not just in the book section, but in the general news sections of newspapers. The phenomenal success of the Wimpy Boy series is attested by the N.Y. Times article about the books. This article appears in the Times's health section and the attention paid is far more psychological than literary. Why is it that a boy who calls himself wimpy turns out to be a hero to so many child readers? Usually the heroes in books for preteen boys are athletic or at least successful in school and in life. Can anyone picture either of the Hardy Boys calling himself wimpy? (Of course the word probably didn't exist when the Hardy boys romped through their adventures.) The Harry Potter books have been a huge success, but they make no attempt to picture the life of real kids in a contemporary world. Perhaps this is why the Wimpy Boy series has reached thousands of kids who think they don't like books. Librarians may not approve, but it's hard to argue with success.