I think everyone knows that a HC needs to be a leader of men. It's really not a controversial opinion.
But, what I also understand is that Gruden is not the only "leader of men" that is available and that no matter what kind of leader of men he is, he also has major issues that will undermine his ability to lead many NFL players, and he hasn't been a good football coach since the early 2000s.
There are lots of ways to lead mean. Gruden's loud in your face style isn't the only way to do it and lots of other candidates, certainly Glenn and Vrabel, are leaders of men and maybe better leaders of men than Gruden. Rizzi is a leader of men, but he lacks the X's and O's to handle a side of the ball and he showed a lack of skills at game management. And there may be others that are just as good at it but we won't know because we don't know them and didn't get to see them on Monday Night Football and other media.
And by the way, Derek Carr also like DA as the head coach so what does that say about who he considers a leader of men?