That term "sociopath" gets thrown around a lot, but it's so far off base, real sociopaths are starting to feel sorry for Steve Jobs.
As revealed recently, he denied Tim Cook's offer of a partial liver transplant. Something that can only be explained with empathy, a lack of which is the primary indication of what's called "sociopathy".
To name just a few more of the signs of sociopath that Steve Jobs didn't fit: inability to plan ahead, lower intelligence, delinquency, violence, financial irresponsibility,...
Basically, what people mean is "he could, at times, be a bit of an asshole". I'm not even sure about your assertion about risk-taking because I can't think of any events that deviate significantly from the risk-taking of similar companies.
It's also hard to say how much his "being an asshole" contributed to Apple's success. Getting people to work 80+ may be a strategy to lower costs, but I don't see how it helps, for example, with the iPhone, created at a time where money wasn't the limiting factor at Apple.