Or the easier explanation, that Elon has changed. He was my favorite billionaire back when all his prospects related to colonization of Mars and all his investments were aimed at creating new technology. But power can corrupt people, and he seems particularly prone to it. The entire Twitter episode is at odds with everything he did 10 years ago; Mars doesn't need a social network, and he's not innovating anything here. Not to mention that part where he's spent the last 7+ years sleeping around and fathering as many children as possible.
A different way of looking at "power corrupts" is that negative social interactions are an important part of the feedback loop that calibrates a person's sense of right and wrong. When a person decides that they don't want to hear conflicting opinions, they loose out on accurate feedback, and de-calibrate, unless they have a strong internal sense of empathy. Empathy is a disadvantage to becoming a billionaire in the first place, so very few of them have much of it. Guys like Musk and Bezos and Trump end up victims of their own success and echo chamber.