A man has to be full of great melancholies to accomplish what he has. This clearly has positive and negative sides. Judging from the accomplishments of great people throughout history you cannot have one without the other.
In the case of Twitter something had to be done. It was too powerful of a public forum and was mismanaged and run by extremists and exacerbated existing divisions, turning them into real rifts. If half a country feels they are being actively suppressed, demonized, and treated unfairly that is a recipe for disaster. Was Elon the guy to fix it? I dunno who else would be crazy enough to try. And his roots are in web tech so his experience may help.