It makes me laugh that the Saban meme- even played up in the commercials he does- is the uptight jerk. Meanwhile, players love him and always have. And while he asked a lot of his assistants, I don’t think guys actually hated him or working for him. But guys like Kelly are actively hated by most people they interact with.
At this level everyone thinks they are studs at what they do, but people lose sight of one of the most important aspects of leadership and management- you’ve got to be a team player and have some emotional intelligence. The brainiac guy with no personality is good for sitting in a back room grinding on analysis, and that is about his effective ceiling. Unlikable jerks will destroy an organization quickly.