I go back to Devenzio often...

(thanks, as always, to Khaddafi for the recommendation so many years ago)

He said something to the effect of, teach in a quiet room, correct in practice, and encourage during a game. In my experience, if you confuse one for the other, all you do is set your kids back. A good coach will definitely get loud, to call out offensive sets or issue reminders, but loud reproach or turning purple is counterproductive.

In my experience, most coaches understand this once it is presented to them properly. If they don't, they need to go find an adult league to play in and stop using kids to play out their inner self-esteem battles.

Positive Coaching Alliance has a ton of great material, supported by research, that helps people understand these concepts. Steve Kerr is a good example.

Brian Kelly is a nightmare. He was not ready to be the head football coach at Notre Dame, and he has been deflecting the blame for his lack of development onto others since it first became apparent he does not have what it takes to grow into the job. Of course, the problem is with those who allow him to persist in this. Maybe he'll win a championship, given enough time. Monkeys, typewriters, Shakespeare...