Only militia are allowed guns, and since we don't have militia, nobody needs any guns. The problem with that is that it flies in the face of historical precedent and ignores the basic intent of the 2A...which was that Americans are an armed people.

No, that is not the argument.

The protection of the Second Amendment did not mean that only the militia are allowed guns. It meant that the federal government could not decide whether the citizenry in any given State was allowed to have guns or not, in order to protect the ability of the State to have a militia that it could draw on if it wanted to. The State was perfectly free to decide whether or not to allow individuals to be armed (and with what weapons), and the federal government could not butt into that.

The question is whether this provision was structured/intended as a collective right to protect State power ("We are prohibiting the Feds from doing this because we need to preserve the capability of State governments to have their own armed forces") or as an individual right ("We are prohibiting the Feds from doing this because we think it is an individual right the people should get to decide for themselves.")

If the latter, then like all the other individual rights in the BoR, the right to bear arms can be construed as a personal "liberty" that is now subject to the 14th Amendment. If the former, though, then the right to bear arms isn't a "liberty" - it's a collective protection from federal overreach that is still subject to whatever rules the States want to impose.