Musk is the classic 'entrepreneur', someone who catalyses innovation by bringing together the technology, the money and the marketing needed to make it happen.
That role does not require him to be the innovative genius or the industrialist, he's found enough of those to serve his turn.
Whatever his role or lack thereof at Paypal, it was enough to net him a substantial stake, some $200MM.
Unlike many, he did not retire with this first fortune, but rather greatly multiplied it with his space and automotive ventures.
Now the automotive and aerospace giants are following the trails he has blazed. Not many can match that.