There are all kinds of people, you can see them here on Slashdot, that know fuck-all about materials science and think 3D printers are magic. They think they are universal constructors, replicators, or whatever other sci-fi tech than can make anything and everything, just in a primitive form. So they think they can advance from playing with plastic to making metal parts that are as strong as forged metals and electronics and so on.
This is, of course, absurd. Anyone with basic MSE knowledge knows that there's a big difference between what you can potentially extrude using a process like a 3D printer does and how you have to make other various materials. It isn't as simple as just printing metal (which I've no doubt we'll see soon), not all metal processes are created equal.
So he doesn't know what he's talking about with regards to materials, which is why he thinks he's such a visionary, and he also knows fuck-all about anarchy. He's one of those loons that thinks an anarchy with no government control would be some kind of utopia instead of what it actually is, a place like Somalia run by warlords.
It all makes me laugh anyhow since he's in the US and could just go buy better parts over the counter anyhow. Oh wow, you can 3D print a lower receiver for an AR-15 that breaks after a little bit. Neat. Or you could just go and buy an AR-15 lower milled from an aluminium billet that will last several lifetimes.