There are a lot of startups that are profitable and have users loving their products that will never sell to Facebook for $1 billion. Using Salmon's argument, it takes pure luck to get to that Instagram-level of success. I buy that. I don't think it follows that all of those small profitable startups are therefore financial failures, which seems to be the conclusion he's drawn.
Hollywood actors are, at best, in the 3-4'th sigma.
I'd agree, if you're intending to be an A-list star and won't settle for anything less, luck is going to have to play a pretty significant role. But there are a lot of jobs and opportunities for an actor, for example, outside the "best of the best" situation.
I was mostly replying in support of the comment above from randomdrake, however.
What you're describing is a "3-sigma" difference, but to be an A-list Hollywood star you'd need to be in something like the 50th sigma. That just isn't explainable by skill.