The guy made Thriller, which is a good, dancy record. It sold a lot of copies. Off the Wall is a good record too, although I like his stuff with Jackson Five more than the solo stuff. He could sing and dance, but I don't really give a shit about dancing.
That being said, he was still a huge weirdo, bought and licensed the Beatles catalog in questionable ways, and probably molested children. He secluded himself in a fairy tale land, didn't want to grow up (because of his messed up childhood) and was an inadequate father (remember the Lion King-esque baby holding thing?)
But I guess it's fitting in death to celebrate what was good about a person rather than the shortcomings.
At least La Toya's still around.