Highly suggest this speech for anyone; creative arts or otherwise.
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.
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.
There is a huge variance in skill in all the creative professions.
I've had the opportunity to work with some extremely well-known actors. Within five minutes of starting working with them, it was obvious why they were so well-known - their skill at the craft was, to a man/woman, extraordinary.
That's something I've found to be the case in other contractors on films, too. Most of the time, in my experience, the 3D artists who get the top jobs or command the highest contracting fees are the most skilled and the easiest to work with, for example.
If you want a really good basic guide to success in the creative arts, I recommend Neil Gaiman's University of the Arts speech:
http://vimeo.com/42372767