In retrospect, I probably should have used a term like "typical" or "statistically representative".
The point is that there are a lot of people who are currently running startups, most of whom are not much like Jobs or Zuckerberg (these are the "average" people). There are also many people who have not started a company, but who might decide to do so if circumstances changed slightly (the marginal people) [1].
In aggregate, both of these groups have just as big an impact on the economy as the few outlier successes.
[1] One might also consider startups which failed, but only barely, as marginal.
