I'm a big fan of Chris' hypothesis, BUT I always tell people "Can you think of one good reason why your first 5 years of experience with building, maintaining, and modifying a first- or second- gen CNC, 3D printer, Xerox copier in active service etc?" At this point they usually protest that they've never done any of that "but they've used them" or worse "have theoretical access to one".
One of the great things about hacker spaces is that you can use such a machine without building, maintaining and modifying it at a level of weekly usage that makes it worthwhile to own. If you want to get that experience, volunteer at a busy hackerspace like mine. You'll quickly learn that 3-D printing "isn't quite here" for routine hobbyist use, even more than, say Linux "isn't quite ready for the casual user's desktop" after 20+years. Don't get me wrong -- I love 3D printing and Linux, and it's hard for me to imagine (sometimes) why it isn't ready for others, but there's a big/learning development curve at each installation, personal or public, and it's not trivial.
So even when chip printing "is here", it won't be "here" for 5+ more years. 10 years, if it keeps chasing the latest promising technology vs completely maturing the last. Flint-knapping is a mature technology, but not many ever mastered it, even among cavemen.