My impression is that he uses his wealth mostly to invest in other ventures that he feels are important causes to him.
I don't understand why so many people seem to hold the attitude that the only acceptable response to someone having money is to pressure them to squander it by giving it all away to atrociously inefficient systems (government, charities, etc). Making money is not immoral. And neither is using money to make investments to make more money.
1) He exploits his workers with typical tech bro enthusiasm, working them to the bone. I hear terrible things about the work culture at his companies. 2) He claims the throne of innovator but many of his successes came from acquisitions which came from his rich parents who ran an exploitative emerald mine. 3) He manipulates the stock market openly. 4) He rarely keeps his promises.
That being said I think he's alright. But it's not just the fact that he uses his money that people complain about him.
The problem here isn’t that Musk is necessarily greedier than any other majority shareholder, it’s that Musk is greedy in a peculiar way that is at odds with so many other people in the world. It’s important to embrace and understand differences, but put too much leverage behind one voice or vision and there will be consequences. And there’s a lot of criticism and evidence that Musk does not use his leverage over others responsibly.