I don't disagree, but the issue is whether a government can keep a working machine gun out of the hands of its citizens. I believe the court will rule that it can. Perhaps one day someone will want a nuclear bomb and argue that the 2d Amendment guarantees his right to it. Apparently the 2d Amendment doesn't apply to Iran or North Korea...thank God.
It's not whether a government can, but whether the federal government can.
The states and their localities have always regulated guns, the Second put no restrictions upon that. Neither has the Second been incorporated (yet) under the 14th to forbid them from doing so.
But this is a federal case. There is no apparent Constitutional authority for this law, and the Miller case is precedence against it. It's a good case if this fellow can afford to appeal.
As an example, the citizen can own a nuclear weapon, but they must store it in a approved nuclear weapon storage facility, under full time military guard, and the weapon itself must be subject to various fail-safes etc to assure it's safe storage and to prevent it's accidental discharge. All the costs associated with this storage will be the responsibility of the owner of the weapon, including the military guard and lease of the storage space etc.
You own it...just like your car it's yours ... no one disputes that... but there are HIGHLY restricted rules for actually firing one. It involves billions in insurance, an approved underground testing facility in an appropriately remote location... blah blah blah... In this way, it's legal under the law for an individual to keep and bear it, but it's still safe for the general public.
It doesn't, they are not part of the group "the people". Although strictly speaking the Second Amendment doesn't apply to the people either, it applies to the government.