You're missing the point. If a "Bump Stock" is banned, the ATF will argue that "Bump Firing" an AR-15 is banned. You can "Bump Fire" an AR-15 with a belt loop, a rubber band, a shoestring, or nothing whatsoever with a bit of practice and development of the skill. Therefore every semi-auto rifle is readily converted into a machinegun in a matter of seconds -- or less -- and therefore by statute, it's a machine gun because it requires NOTHING whatsoever to be a "Bump Fired" machinegun. Therefore all semi-auto rifles and shotguns are BANNED machineguns. Read the law. Anything readily converted into a machinegun is a machinegun. You're ignoring how desperate Biden and his ATF minions are to completely disarm everyone and they'll use every conceivable hook they can imagine or invent to do so.
Turns out a really fat belly can act as a sort of "bump stock"! I've seen it on YouTube! So really fat people are literally a machine gun! I am not sure I am a machine gun though. I'm fat. I'm not sure I'm fat enough to really get the bump stock action going on.
Seriously though. The solicitor general argued that belt loops and such are not machine guns when questioned about it, because belt loops don't automatically control the sequence like bump stocks do. Not a plausible rebuttal, but the justices don't know enough about it to call it ********. Point is though, their own argument excluded belt loops, rubber bands, bellies, whatever else, from being a machine gun. They're arguing about the device.