Like Richard Branson?
And with the possible exception of Branson, none of them are close to doing as big of things, with as much success, and as much inspirational flair and passion, as Musk.
He starts the criteria with "billionaires".. 0.000000215% of the worlds population.
Then to narrow it down farther he says they must be working on 'cool sci-fi shit'. Ie: they can't just be doing innovative things, they must be sci-fi things, and even if they are sci-fi, they must be 'cool'.
Of course there are only a few people who meet that criteria.
There's a lot of ways to contribute to society, to each their own.