Or -- he's stupid.
I suspect this is the real problem. Stupid people with money can look like they are clever because the layer of people immediately underneath them actually wields the clue stick. Stupid people with no money look stupid because they can't afford the layer of clever people underneath them. Clever people are either abstracting the liability via stupid person in the layer above them or don't need that kind of shit in the…
A similar but more charitable theory is that Elon is very good at leading a company to build actual hardware that has to solve hard physics problems. At twitter the primary challenge is managing people, and he is autistic and has no idea how to do this. He has no idea how normal people experience or use twitter, no idea how his tweets are felt by people, no idea how his employees feel about him etc.
all of these are things that don't matter when building a rocket or a car, while understanding people and politics is the ONLY thing that matters at twitter.