That's actually touched upon in the article (I'm the author). In short, it's possible - but not given: 1) The culture of knowledge- and-design sharing has been

That's actually touched upon in the article (I'm the author). In short, it's possible - but not given: 1) The culture of knowledge- and-design sharing has been prevalent in the DIY community for decades, but hasn't produced anything comparably grand. This is despite the fact that we can already easily source or make custom parts of all sorts. Will this suddenly change? Who knows. 2) There is extremely little emphasis on materials science and mechanical engineering in the 3D printing community at this point - which makes it difficult to reach a "critical mass" of good, practical CAD models to reuse (there's plenty of Yoda figurines to choose from, though). The success of the open source community owes a lot to the broad availability of high-quality reference materials and the self-documenting nature of most of the existing code. 3) The dominant FDM approach produces inherently crappy parts, which makes it poorly suited for direct manufacturing. There is no clear path to fixing it. The alternative technologies work better, but aren't as simple to operate. Of course, better approaches will eventually arrive at some point - but would require major breakthroughs, not incremental tweaks. 4) There is very little "portability" of designs not only across printing technologies, but even between individual printers - which again, is an interesting handicap.