One thing I'm noticing across multiple sports is that too many head coaches do not want to work with players that will likely never play a meaningful varsity game. They only want to work with the players that will help them win. IMO, this mindset is coming from travel sports. HS sports are not meant to be this way. Extra-curriculars are an extension of the classroom and if there is space available, any reasonable player should have a spot to play.
As one example, I know of a sport (not baseball) that has 36 travel ball players and the HS is cutting down to around 24 (Varsity/JV). That will leave 12 travel ball players cut and a few rec ball players. Those "extra" players are more than enough to field a JV B team. Schools should always have to field 3 teams if there is enough interest.
I see it in soccer where club coaches take HS jobs and the varsity team becomes an extension of the club. "If you don't play for me in the spring, you're not playing for me in the fall."