Now that the seven book trilogy has been completed, it has come to light why Professor Albus Percival Wulfric Brian Dumbledore was killed off before the series was complete.
Apparently the character had a showdown with Rowling, demanding to be killed off.
"He spoke to me shortly before his death," said minor character, Dean Thomas. "He was fed up with the shoddy writing, convoluted, ill-conceived plots and lousy characterisation. He always maintained he was more than a long beard an a hat."
Thomas went on to reveal that Dumbldore and Rowling had a vicious argument between book five and six in which the headmaster of Hogwarts threw a massive diva fit, and promised that if he wasn't written out of the next book, he would side with Voldermort and really screw with Rowling's plot. Apparently, he also took issue with the way he was portrayed by three separate actors; splitting his image rights into three.
Rowling acquiesced to Dumbledore's demands, but did coax him back for a cameo in the final book.
Dumbledore insists that he will be doing no further collaborations with Rowling; unless she takes a creative writing course, and learns when to use a semi-colon. Rowling and her publishers are currently in negotiations with Dumbledore to portray his early life, but at the moment this looks unlikely to come off.
Dumbledore was unavailable for comment.