This indeed is the gospel truth. In my opinion, pitch counts are the concession that travel ball coaches make to make a pitcher throw all year, which simply wears their young arms out early and which is, in my opinion, highly inadvisable. Then they never get to build up any endurance.
Pitch counts are there because coaches can't seem to put kids best interest ahead of wins. When we moved to Alabama last year, coach talked about how much he cared about arms during the visit we had with him and that same day allowed his step son to throw 178 pitches in a 7 inning game.
Last season, my son said an opposing coach said they named the pitch count rule after our coach. I think the NHSF pitch count recommendations or pitches and days of rest are reasonable. 120 pitches is a good stopping point for most high school kids.
All travel ball my son ever played wasn't based on pitch counts. It was based on # of innings. That is why pitch counts are needed. 9 & 10 year olds could throw 3 innings and still pitch 5 more the next day. We saw kids throw 60+ pitches one day and then 100 the next. That can't be good for a 9-10 year old arm. Many of the kids who were "aces" at that age never made it as a good pitcher in HS. Some were just early develop kids who everyone else caught up with in size. Some just seemed to lose velocity. Many of those were kids who were IMO overused.
One upside of pitch counts is now coaches have to develop more pitchers. I am seeing more kids who had never pitched before being given a chance.
Now once kids get into pro ball and once bodies are mature, that is a different matter.