Here is what I know:
Historically, the AMA has really only provided three things, Insurance, organization/regulation/standardization (where safety and competition are concerned) and advocacy. Over the last decade or so they have proven beyond a reasonable doubt (to me) to be unable to advocate in order that its' members not see new regulations, so advocacy is off my list. Insurance can be had outside of the AMA, so that one is off the list. The only other "value" item on the list of things that make AMA relevant is the organization/standardization/regulation, and that is only important to those who compete, which likely accounts for less than 10% of the membership.
What I am trying to say is, it really wouldn't be that difficult for a group of non-competition, recreational flyers that has a flying field to adopt the AMA safety code, obtain insurance, petition to be recognized as a CBO and walk away from the AMA. The AMA DOES NOT OWN US, and they really can't keep us down with their thumb, despite what they want the unwashed masses to believe. Of course, the more clubs that want to unite, the more legitimacy they would have, and the better insurance rates they would get.