You make a number of true and good points, but what I'd say is that you actually support my overall arguments in the article:
1) billionaires are morally complex and often do more-than-questionable things, of which you cite many examples - I believe that billionaires, at least those which do build their own wealth (or most of their own wealth), achieve a net positive effect on humanity in spite, not because of, these significant issues.
2) governments, it follows, must step in and take considerable action against the ills of billionaires and companies, with far better anti-trust regulation, workers' and environmental protections, as well as consumer protections.
Of course the moral blame for the shortfalls and, frankly, crimes of some billionaires lays squarely at their door. But billionaires, as I pointed out, are (rightly) unaccountable to the people. They are accountable only to the government and the law, so we need to pressure the government (as you correctly conclude).
On the point about Zuckerberg and Facebook in particular, I agree that they got it horribly, horribly wrong in 2016. Their efforts this time around, though, to prevent abuse of the platform for political purposes, should be commended - although we are yet to see the effect they have, which will become apparent closer to and in the aftermath of the election. I think Zuckerberg has made many significant and consequential mistakes and errors of judgement. What I don't buy is the idea that Zuckerberg doesn't care or doesn't want to change - he is making an effort this time, and the appointment of Nick Clegg, the former UK Deputy PM and noted liberal, is a good sign of this.