Just because you adopt the first part (ownership before membership) as important, doesn’t mean society, and the pre eminent law of the land can just give up on the second.

I agree completely, but that’s still irrelevant to the question of the right to keep and bear arms in the first place.

I mean why are the vast majority of gun owners not affiliated? Not trained?

This is largely how Switzerland works, for example, and they’re a perfect example of why people should be affiliated and trained.

But to answer your question, the dual role of militias as both external defense and internal peacekeepers has unfortunately been usurped. On the one hand by the growth and sophistication of the US Armed Forces, and on the other by the originally racist and anti-working class organizations that later became police forces. The latter highlights even moreso the reason why the right to keep and bear arms is so important (as well as the importance of self-organization of those keeping and bearing the arms!), and it boggles my mind how eager people are to give it up with everything that’s happened in the past few years, especially women and minorities.