>but they are not really any less disruptive.

Where's the disruption exactly? Everytime I look at the 3D printing scene its a bunch of neckbeards printing Star Wars figures and other useless knick-nacks. What industry has cheap 3D printing attacked? The argument seemed to be "Oh we'll make spare parts and such," but that never happened. It was supposed to make a new market, but seems to have completely fizzled out.