Errors in your description of 3D printing and your assumption that there are idiot-proof 3D printers (there aren’t) lead me to assume that you don’t have much personal experience with the process. There are lots of people currently monetizing 3D printing in niche markets, but the only ones doing really well are those who provide specialty services and/or short run production to industrial clients. As in any other technical arena, there is always room for innovative marketing and delivery of services in 3D printing. That said, neither “plug and play” nor profitability in the one-off consumer market are viable business plans at this time. I do like the value proposition; the technology just isn’t there yet.