I wrote the article. In it, I clearly outline that the topic of discussion is -- specifically -- childlike wonder and what happens when it mixes with wealth. Not "that every wealthy person should behave in a particular way."
In fact, I would argue even that Gates' path is even far more crazy and childlike. In order to do what he has done, he's had to get out of the relatively clean, logical bubble of technology and deal with messy, real world politics to accomplish his goals...and yet he still pushes forth in idealism. Contrast this with Musk, who after a less-than-favorable review in the New York Times, threw a fit. I'm not saying Musk was or wasn't justified, I'm pointing out that real world revolution takes both child-like wonder and an ability to handle out-of-your-realm realities...Gates is farther along in this difficult path than Musk, though I agree, Musk is more likely to have an Iron Man-like movie made about him.
This was not the claim made by GP. He did not object to any attempts to prescribe behavior to billionaires, his objection was this:
> "if shit ain't being blown up, then who cares?"
Which is an admittedly snarky summary of your post, but accurate. As you said, your complaint is that people aren't doing enough to inspire childlike wonder.
Except they are - Borlaug as a good example. He saved literally billions of lives, revolutionized our every day lives, and has changed the face of food forever using science and technology. When he died, the bulk of HN didn't even know who he was.
Likewise, others in this thread have brought up a great many people - many of whom billionaires - who are doing "cool sci-fi shit", where "sci-fi" means more than putting stuff into low Earth orbit.
The answer to "why aren't more people doing cool sci-fi shit?" is "you need to look harder, because cool sci-fi shit doesn't always have a solid fuel booster attached to it".