You are partly correct. I say this with as little ego as possible - I am mechanical engineer at a product development firm, and a member of my local hackerspace. I design consumer products every day, and know people that are working on 3D printers for the home. The mailing list for the commercial extrusion-type printer we use at my makerspace is continually riddled with "why is the printer down today?" We don't have a printer in my office because maintaining them is such a pain in the balls. Home users will not accept this. I can hardly design good products because I have to user-proof them so much.
Consumer printers like the Cube, Makerbot, etc. are perfectly suited for printing toys off Thingiverse, and little else. The market really just isn't there. This link is one of the best editorials I've seen for trying to explain why prices won't fall in the way that they did for desktop publishing:
A 3-D Printer For Every Home! (Yeah, Right) | Co.Design: business + innovation + design
Yes, I tried to cover this on the last thread. Prices will come down, you will know people that have them. You will know people that own them. You may even know people that decide the hobby is important enough to them that they'll buy a real one rather than investing in a Barrett or a motorcycle, either of which is less finicky, and requires less specialized training to own/operate/maintain.
What you will not find any time soon are $300 printers in your home that produce durable engineered parts. Not in 5 years, not likely in 10. Probably never because as was so well said in the article "WE JUST DON’T NEED THAT MUCH CRAP." The cost-benefit does not weigh in the favor of FDM in the home, let-alone the SLA/SLS and similar technologies that Cody's designs rely on.
While it is possible to make them at home, and in the case of popular revolution, possibly worth the risk, Your average home user won't be printing Liberators or lowers. Mags, I can see, and that's potentially a great use of the technology even now.