In the book "Masters of doom", at least during the doom era, Carmack seemed like a really bad collegue. Very, very demanding and complete lack of social tact. The book gave the impression that he wanted everyone to be as commited as him, and his commitment was extreme.

Obviously this was a few decades ago.

It is just the feeling I got from reading his dev. diary. Nothing but a feeling that I don't want to work for him.

Elon Musk seems very timid and shy. I was surprised when watching the "steel ball fail". He was nothing like what I imagined him.

It is really hard to tell people characters by video appearances.