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