I don't think it is any coincidence that rampantly unstable people make it into the realms of entertainment stardom. There's a theory that bipolar people, for example, are only brave enough to do what they do on stage when they are on a "high" - they really do believe they are the best in the world, it's confidence gone mad. Then the lows set in and they self-medicate with drink and drugs to get through it and back to the creative mood. Not sure if that was Jackson's particular problem but he was certainly weird in some not-quite-normal-mental-state way. So not making old bones is almost normal for rock stars.

But among Jimi Hendrix, Janis Joplin, James Dean, Marilyn Monroe, Phil Lynott, John Bonham and so many others, Jackson managed to be SPECTACULARLY weird for such a long time. It is a wonder he lasted as long as he did.