Many famous scientists, engineers or industrialists who moved the world forward in the past were racist or total Nazis. Today, many otherwise extremely smart people exhibit the same behavior as Musk, you just see it publicly in his case. I see it a lot in high level academia circles. The antivax and other conspiracies during Covid got a lot of help from very intelligent people, in my state the leader of the highest rated university got involved in that, for example.

You shouldn't mistake his Twitter feed for straight and full approval... He often trolls or merely thinks there might be some basis of truth in something, and sometimes he blurts out in anger. Again, in his case you just see it publicly.

Not defending him, it's weird and terrible and took a sharp decline after his breakup. But it's not so unusual.