The best "attitude" I have ever seen in any car club is that of the Studebaker Driver's Club which is a huge organization with many thousand members, with (last I heard) almost a million dollars in the bank, many dozens of parts vendors, an outstanding color publication, incredible national meetings, great people, hundreds of reproduction parts and I could go on and on. So I ask myself WHY ?
Now certainly there were many more Studebakers built over many more years - I'll grant you that and it contributes to the answer. But I genuinely believe it is because the Club embraces everyone who wants to join their niche of the hobby. From purist restorers to customizers to salt flat racers to hot rodders all are welcome. And thus all contribute and all share. The hot rodder doesn't need that original overdrive unit but the restorer does. The customizer still needs a reproduction windshield even though he may cut it for his chop top. The racer can contribute a disc brake conversion the hobby driver can use. They all work together. They "get it". This "big tent" approach works.