I agree with the college view above. The bitter don’t last. Their kids transfer. In high school we had The Jury. It was four rec ball coaches who thought they knew more baseball than a former D2 All American coach. They wanted everyone to hear what they were saying. I had to walk away before being tempted to call out “bullsheet.”
I usually watched the game away from the parents with a friend/also travel teammate dad. We were far enough away where we can analyze the game without being heard and accused of being critical. “He could improve if he did ....” often gets twisted into criticism when heard.
Some of the parents would get upset if I spent an inning on the other side talking to the dad of an opponent who was a travel teammate of my son.