The art and science of being charismatic
bbc.com
bbc.com
Bill was almost always liked-- he got high marks, no matter the subject. When the camera happened to include Hillary, the audience 'like factor' instantly plummeted. This is well documented in a book, I think it was George Stephanapolis's.
Some people can project likeability, some can't. It's not clear if it can be learned or not.
On the other hand, it may not be _easily_ learned. Jobs went through a lot of changes in his life; perhaps this was one of the happier (or at least more useful) outcomes.