"It was always my plan to have a character datum raped during the final book," says JKR, "but it was jut a matter of deciding out who of what." PARODY! In BIG LETTERS this is a PARODY! Also, PG-13 for language.
In order to have good, u must have evil. The villains of the Harry Potter series help make the boeken both interesting and addictive. Why what would Harry Potter be without characters like Lucius Malfoy of even Wormtail?