Yeah, I'll cede there's plenty of bad ideas. I don't think 3d printing is one of them, I think we'll printing all kinds of things, including houses and cheeseburgers. No, not with the current nylons and acrylics, but the tech is on the march, and it doesn't take a huge leap of imagination to see the day when 3d printers are aligning molecules precisely to create whatever the hell we want. Suppose you wanted to make a superior sword. Can you imagine a day when a 3d printer can arrange each particle of material to achieve optimal atomic arrangement of iron and carbon to create something far superior to something that can be created by the world's greatest craftsman? It's a not even a big jump from that to printing the perfect cheeseburger. The author can't see that. I think that's his limitation.