P51B-
Your position and Homebrewer's seem the most level-headed to me. Don't think I would even call the guy rude and inconsiderate based on what what little has been said about him. For all we know the club is run by a real jerk, dues are exorbitant, it's in a toxic waste dump or swamp full of 'gators, etc. Point is, he doesn't want to join the club, and whatever his reasons may be, he doesn't have to.
He doesn't belong to AMA, ergo he doesn't have AMA insurance and the long laundry list of conditions that go with it, including the 3 mile separation thing called out in the Safety Code. IOW, no law or sanction obligates him to observe 3 mi separation, but club members are subject to it by their contract with AMA for insurance. Club members knowingly flying within 3 miles of another flying site without a frequency sharing agreement are in violation of the Safety Code, possibly nullifying their insurance coverage that probably is 99% of the reasons they chartered with AMA to begin with.
HC can talk hardball (he's a hardball sorta guy<G>) , but I think the situation calls for diplomacy. The guys that say offer free membership, or simply give up a frequency to the 'rogue' (that moniker in itself shows an arrogant posture toward him) are on the right track toward reaching accord. He appears to have every right to do what he is doing, according to any agency that has any domain over him. The club is already on thin ice with their own organization/insurer by not suspending operations until some agreement is reached. Not what anyone wants to hear, but that's the real world. The world where AMA grants to each sanctioned club exclusive rights to over 28 square miles of ' R/C frequencies space' isn't the real one.

Abel