Steve Jobs sits at the core of what Apple represents by his attention to detail down to the aesthetic micrometer. There is an almost sinister genius in what he does at Apple, and at the end of the day you end up with a consistent, applicable and fluid user experience at every level including sales. People want to be involved in that because they know what they're getting. Apple constantly proves itself as a company that does more than talk about thinking outside the box. They think outside the shipping container, and down the street some.
Steve Jobs is an entrepreneur who knew attention to detail, and consistently pushing the envelope beyond a "good product" will bring in dollars.
Zuck sits at the core of a social networking behemoth that has no clear sense of direction, constant changes to using the site, frequent controversy about privacy, fragmented user networks, and no consistency in approach.
Mark Zuckerberg, as much as some people will suffer from bleeding ears after hearing (reading) this: got lucky.