I've always found the reports of his behind the scenes behavior and its stark contrast with his public persona to be incredibly disturbing, because it paints a picture of someone with psychopathic tendencies. I suspect there's something really dark with him that originates in his childhood (suffered through horrific bullying and a hellishly awful father).
This may sound a bit weird but haven't you noticed they all are psychopaths? Although high functioning ones. Mark Zuckerberg, Bill Gates, Jeff Bezoz... These are not healthy people mentally. But they are rich and powerful.
Musk said he is in the asperger spectrum. Among other things, it generally makes you not care what other think about you. And may lead to behaviour that is "acted" because all social interactions may be a difficult exercise.
Humans are complex and deep. And sometimes awful. There are more dimensions to a person than a good/bad guy or psycho/normal.
And with asperger - neurological diversity expands this space in ways it makes it very hard for neurotypicals to intuitively tell what the hell is going on.
Nobody is excused for bad manners. But not having any would not make person a psychopath.