Admitting it as a consideration really doesn't mean much, all sides have people arguing points that the majority of people supporting that point don't really believe in. It is patently dishonest (though a standard rhetoric tactic) to ignore the more legitimate arguments and focus on these minority arguments. It is plain that this is what is happening here. You don't win "a point" for it. You only win a point if you can prove that this changed the debate, and this you won't be able to do.

The simple point is that militias pre-date slavery in North America and were considered essential for a democracy. From the Greeks down to modern times, the citizens right to bear arms was a bedrock for democracy as opposed to federal power. Nearly all the arguments were based upon this belief so again you would have to ignore all of history (and the founding fathers knew their history) in order to focus on the minor point you want to make the focus.