What about the Check Captain who appears to be aggressive and unreasonable? Is he really aware of why he or she is behaving that way? That person may have had a really abusive childhood and has learnt that the only way to be in control is by using fear as a method of survival so that they themselves will not be in a position where they are not in control. Yet their lives may well be run by something that is still in their subconcious mind that they had long forgotton. Something that wounded them when they were very young. Yet they are doing the best they can because they don't know any other way.
So why do they get promoted? People with these sort of problems should not be in charge!
I find it astounding how people in aviation who in other industries wouldn't last 5 minutes seem to move to the top of the tree