I must respectfully disagree. I take your central argument to be: "3D printers won't ultimately change our manufacturing process." I take your main points to

I must respectfully disagree. I take your central argument to be: "3D printers won't ultimately change our manufacturing process." I take your main points to be: 1. The materials are weak and thus unsuitable for most products and 2. The efficiencies of scale of traditional manufacturing trump 3D printers in runs above 1k units. Today your first point is true, however I use 3D printed parts as structural components in my robots and they are sound. I suspect in general material strength will increase until it meets the demands of how people want to use it. I hope you wouldn't make the argument that it can't increase in strength. There will always be material properties that can't be replicated in a fabber, but I do not know how many products in my life need these advanced properties. Your second point ignores the decentralized nature of 3D printing. In total, yes, it will always be less efficient. But imagine a world where an Apple product launch means access to a new fabber file. Everyone in the world with a fabber could download and print the new product ... at the same time. No centralized manufacturing and distribution network could match that. Some additional hurdles you don't mention: Material cost. $6 a cubic inch (my costs today) are really quite high. Material diversity. I need multiple materials for many objects I'd like to print. Speed. It takes hours to print something of moderate size. If I can pop over to a store and get the same item manufactured in the traditional way, I probably will. Finally, if by any chance, someone reading this comment hasn't read "The Diamond Age" by Stephenson, please do yourself a favor and pick up a copy.