He created a company from scratch that builds rocketships. A company that has launched a pressurized capsule into orbit. If his company was a country there would have been a human in that capsule and it would have made a lot more news than it did, as it was it still stands as an impressive achievement. And achievements give you a lot of credibility.
Impressive, but not sufficient to explain the power of his personality - which is enormous. For example, Orbital, a public company that builds rocketships, was also started from scratch by one man with a vision (and without the resources of Musk, I might add). And yet you've likely never heard of them.
There are lots of experienced, credible people who cannot do what Musk does with his outrageous dreams (and they are outrageous - to Mars and back for the cost of a upper middle class home in the US - think about that). To dismiss his impact as the consequence of success is to miss the true source, I suspect.
