RJM,
It stinks, no doubt about it. But this decision by the coach is no different than any other decision(playing time, position, batting order, etc.). All coaches do things differently. He probably has a history of parental interference and he has decided to stop it cold turkey. The bad thing is he decided to do it with your son's team. I bet he will relax a little next year but you never know. All coaches are changing in their style as they go along.
Your choices:
1. Stay on the team and play your hiney off.
2. Quit.
3. Transfer.
4. Move back to Cali and play in one of the spring leagues and do travel only.
5. Go to the AD and try to get the coach fired or gutted of authority.
1 amd 3 are your only true options. If you pick 5, he will probably quit and you will have a coach who knows nothing. A fill in guy. And next year when the new coach is in place and some other parent is unhappy, here comes the axe. No coaches are perfect(but there are a few on this board who are pretty dang close) just play ball and ignore everything else. Or leave. The same choice that all of your travel parents have when they don't like your policies.
Whatever you decide, I will be willing to bet that your coaches policies will get better with time and experience.