Now, he didn't always win (most memorably in his ejection from Apple by the board), and sometimes this egomania had catastrophic effects - from his personal life, and most likely to his own health, where he refused to accept other people's opinion of what the best course of action was. You can argue and shape some people minds, but ultimately you can't win an argument with nature.
It may very well have been the case, that without the bad, there could never have been the good - they were inexorably linked.
I think there's something important to this notion. I once read a biography of Churchill that suggested Churchill's distrust of Hitler in the 1930's partly sprang from Churchill being the kind of egomaniac who could recognize an egomaniac. I'm sure I've done neither Churchill nor the book justice in this description, but I think there's support for the notion that personality doesn't simply or easily decompose into good parts and bad parts.
[1] 'The Last Lion: Winston Spencer Churchill: Alone, 1932-1940', William Manchester
It does rather support the idea that hero worship is a really bad waste of time at best, and downright dangerous at worst...
Putting Pixar's success on Jobs alone is a huge disservice to the true believers that actually built Pixar.