Of course, one can manufacture a gun from a 3D printer plus some additional stuff. But there is a qualitative difference between 'click print' and you get ever

Of course, one can manufacture a gun from a 3D printer plus some additional stuff. But there is a qualitative difference between 'click print' and you get everything you need and a project to get everything you need to build a gun, which utilizes a 3D printer ( and some chemistry and some additional metalwork). After all, it is today possible to manufacture a (completely unregistered) gun yourself utilizing a CNC cutter and some craftsmanship.