[0] Sure, he got fired, but with a net worth of $500 million. Doesn't count. I'll let you fire me five times for a tenth of that. You can even do it in public. Hell, even have Donald Trump do it.
While it's arrogant to say this, I think I have nearly as strong a design sense as him. I honed it studying the German style of board games, and eventually writing my own games (most were failures, but I learned from them and got good). I optimized a trick-taking card game (Ambition) to drive out card-luck. Not an easy thing to do. After years of playtesting and throwing out things that suck and rebalancing, the damn thing plays well.
I was also a bit "youthful" in my self-promotion, got into some pretty awful flamewars on Wikipedia. I can't exactly hide that. I was 20. Shit happens. I certainly understand the mental "edge" that turns top designers into arrogant people. It's there, and it's part of what drives you to be great, but it also needs to be checked. Not because it's offensive or morally wrong to be a jerk, but because it makes you suck. If you're unaccountable for the quality of your ideas, you'll have bad ones.
When people see Steve Jobs's behavior, they see what someone like me would be like without a few hefty doses of humility (some deserved, others not) in my 20s. ::shudder::
As a competent-or-better designer, I will say this: you don't have to be a jerk to get good designs. In fact, often what you do as a design lead is take in other peoples' ideas, and moderate. If you shut people out (or scare them) you're losing signal for no good reason. You need all the signal you can get, because good ideas come from everywhere.
I think Jobs had one positive effect, which is that he burned away corporate bullshit. I'm sure that there was as much politicking under him as under any charismatic leader, but I think a Jobs-like figure makes it just too embarrassing to let corporate boondoggles get into the product. I'm sure there was just as much nastiness as anywhere else, but that the more successful lieutenants knew that a product that mirrored internal politics (Conway's Law, applied to design) should be shredded to pieces.
So maybe it does take an asshole figure like Jobs to keep a corporation from devolving into design-blindness... not because design requires assholes, but because of what corporations are.
That said, I can't stand the goddamn fake Steve Jobs's who use him to justify being an asshole. I am closer to Jobs than 99.5+ percent of them and not nearly as much of a jerk (I have my moments, but I fucking work like no one would believe on patience.) If you cite Steve Jobs to justify bad behavior (I've encountered this a million times) then you are an idiot because most people who behave badly are not Steve Jobs.