I live in VA & recently heard an interview on MLB Radio with Billy Wagner who is now a HS coach in VA. He was asked on this issue & was adamant about letting his kids call their own & learn the game. The focus was clearly on player development from arguably the top LH Reliever to ever toss it. Winning was secondary to him although the team was well over 500% at the time of the interview (about a month ago).
From my experience it is mostly a case of the coach not having the ability to tuck his ego in his back pocket & let the kids play & learn how to play from their mistakes. I got paid to pitch for 7 years & yes, I have called some from time to time & this is typically in a big spot & I will send one in or work a sequence, but for the most part we let them go at it & then if something comes up we will review. It is the coolest thing to have your 13U catcher come to you after an inning & ask if you thought the 2-2 pitch that was smoked was the right pitch or not. Often it was & sometimes you give the hitter credit. If we feel it was not we can discuss why . The point is that the pitcher learns to have a feel & the catcher has to think.
We had our shot & now it is their turn. Let them go.