But as the nation as a whole - other than a very small minority - feels the security of the free state is quite well enough protected by the regular military, the military reserve, the national guard and various police forces, the need to form militias seems somewhat reduced.
Even if your conclusion is correct, the right is still protected by the Constitution so that in the case that more people become convinced that the security of the free state is in jeapardy then they can do something about it.
Further, I'm wondering where you see the interpretation that such a militia is to defend the security of the free state against its government.
From Federalist Paper #46:
[Note: The supposition referred to is (roughly paraphrased) that bad leaders are elected for long enough to allow for a military state, that said military power would be used to hold down the people.] Extravagant as the supposition is, let it however be made. Let a regular army, fully equal to the resources of the country, be formed; and let it be entirely at the devotion of the federal government; still it would not be going too far to say, that the State governments, with the people on their side, would be able to repel the danger. The highest number to which, according to the best computation, a standing army can be carried in any country, does not exceed one hundredth part of the whole number of souls; or one twenty-fifth part of the number able to bear arms. This proportion would not yield, in the United States, an army of more than twenty-five or thirty thousand men. To these would be opposed a militia amounting to near half a million of citizens with arms in their hands, officered by men chosen from among themselves, fighting for their common liberties, and united and conducted by governments possessing their affections and confidence. It may well be doubted, whether a militia thus circumstanced could ever be conquered by such a proportion of regular troops. Those who are best acquainted with the last successful resistance of this country against the British arms, will be most inclined to deny the possibility of it. Besides the advantage of being armed, which the Americans possess over the people of almost every other nation, the existence of subordinate governments, to which the people are attached, and by which the militia officers are appointed, forms a barrier against the enterprises of ambition, more insurmountable than any which a simple government of any form can admit of. Notwithstanding the military establishments in the several kingdoms of Europe, which are carried as far as the public resources will bear, the governments are afraid to trust the people with arms. And it is not certain, that with this aid alone they would not be able to shake off their yokes. But were the people to possess the additional advantages of local governments chosen by themselves, who could collect the national will and direct the national force, and of officers appointed out of the militia, by these governments, and attached both to them and to the militia, it may be affirmed with the greatest assurance, that the throne of every tyranny in Europe would be speedily overturned in spite of the legions which surround it.
Although the Federalist Papers do not carry any weight of law, they were written to argue for the formation of the Federal gov't, and to address the concerns that folks had about the formation of the Federal Government.
There are many writings from that period of time that treat gun ownership as a god-given right. The rights mentioned in the Constitution are not granted by the Constitition, they are protected by that document.