JohnF,
You hit on another point. Why stress your son's arm out as a preteen when you know for a fact in HS he will put in more time than he should because of showcases and tournaments to be seen by college coaches,scouts etc.
Parents with young players eager for them to play as much as they can do not realize all that will be required from them in HS.
A very good friend of mine who was once sons travel coach in middle school played for UM. He really helped me to understand that it wasn't really important to play during certain periods of a young ball players life, especially when one showed tools that would get him a scholarship in HS or maybe even drafted.
If some can understand what I am sayin' that's good, if not, I know that I tried.