My parents are friends with a number of old high school coaches. They identify the problem in youth sports as the parents. The parents are the ones being overly involved, demanding, whiny, pushy, etc. If people are going to blame the teenager for every bad coaching situation, that's short sighted. Kids often are responding to their environment that is shaped by family, community, and peers than more than anything.
But I also had a number of experiences with coaches that were sort of nuts with crazy, intense yelling act. It's sport, so i don't expect a group therapy session, but it was a little over the top, in retrospect. What that ends up doing, more than anything, is engender fear and destroy confidence.
I had two high school running coaches, one that was old school and probably practiced what would now be considered improper behavior. The other was very positive and did not take the yelling and super critical route. The first coach had some early success, but he lost control of the program after awhile, and left more runners than not with a bad tastes in their mouth. The second coach had immediate success with runners of dubious talent and the program in more popular and stronger than has been in 15-20 years. In my teenage years, I would have defended the first coach because I had success in his program, but we lost a lot of talent because he was a passive aggressive a-hole. As the years wore on, i realized why his coach style no longer was effective.
The fact of the matter is that if a coach wants to be a raging a-hole today, there might be consequences. Sure, they might have some success that smooths over the rough edges, but if more people are having a negative experience with the coach than anything resembling growth in athletics and life, that might be a problem.