Strangely, it was partially because he was so insufferable that Apple became as successful as it is today. Steve Jobs was notorious for being in-your-face brutal about the quality of work being done simply not being good enough. Crying, screaming, throwing tantrums - all these histrionics went hand-in-hand with that.

What's interesting about this is that Steve had two things that most people lack: (1) vision in spades. And more importantly, very good vision. (2) an ability to push people beyond their limits by berating them, but then having really amazing work come out of that process.

Steve Jobs was awe-inspiring because he could dress people down and grill them on details that most other people either didn't notice or would gloss over. If you read many of the books about Steve Jobs, there's a common refrain said by many of those who worked under him.

"I'd never work for him again, but he pushed me to do things I never knew I was capable of."

[EDIT: forgot to add] The reason Steve was able to get away with all this negative behavior is that it produced amazing results. But for most people, being so belligerent and nasty without having an amazing vision to back it up will not get you very far. And, for the most part, such people are completely egomaniacal. (Steve was too, he just happened to be right a lot).