It's always been clear, except to his weirdly cultish fans, that Musk just isn't a terribly wise or deep guy. He might be a good engineer, and he might be a good entrepreneur, but he's definitely not an intellectual.
And while you needn't be an intellectual to run Twitter well, of course, quite a lot of the biggest issues Twitter deals with aren't engineering problems, but more ambiguous issues of values and social incentives. These demand thoughtfulness, and Musk just isn't very thoughtful.