I'm probably somewhat the person you are complaining about here. The current desktop 3D printers are pretty useless for anything functional (but fine for initial aesthetic models). All these people have grand ideas of being able to print functional products at their desk and there are some significant technical challenges that need to be solved yet. I don't believe that any of the current printing methods are ever going to get to the point where typical consumers will truly be happy with them, especially when compared to injection molded parts. I think the technology that may eventually accomplish what I consider to be fully functional will not look at all like we have today and it at least 15-20 years away.
On the contrary, I wouldn't be surprised if there is a continuous path from the current 3D printing technology to the eventual mass market technology.
I see strong parallels to the early history of inkjet printers. From the 1976 IBM 4640 "ink jet" to the Thinkjet took 8 years, but the technology shows a clear lineage. Inkjet printers struggled with many of the same teething issues. See this 1985 article explaining the challenges: http://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1985-05.pdf
I recently mounted a 3D printer, because I had a need for it. Now, some parts for my design are stopped at customs, so I still didn't use it (except for a small fixing at home), but I already have a new project that will need the printer.
