Just making something that looks the same does not mean it will perform the same.
For example, would the lemon juicer in the picture withstand the dishwasher for as long as the shop bought equivalent? If not, how many times would the printed version be replaced and at what cost?
I just don't yet buy, in the examples given, that the items are of equivalent performance, and that is if one were to generously say that they had equivalent aesthetic qualities.
3d printing will get there, but it's not there yet.
A guy at the local hackerspace successfully printed a beefy motor mount with ABS. He also helped me design a tripod mount for holding my Nikon D600 vertically (lens pointing down); I have no concerns about it failing, even though the mount is going to be subject to CNC movements.
(Lightbulb) you know who really needs a good 3d printer? My local family-run hardware store
Then they used Google Shopping to determine the maximum and minimum cost of buying those 20 items online, shipping charges not included. Next, they calculated the cost of making them with 3D printers. The conclusion: it would cost the typical consumer from $312 to $1,944 to buy those 20 things compared to $18 to make them in a weekend.
Oh come on. Like all those items online were made out of the same low-melt-point plastic and the 3d-printed ones were of equivalent quality. I'm very much pro 3d-printing but there's some serious reaching here.
The last page of the study (http://www.academia.edu/4067796/Life-Cycle_Economic_Analysis...) offers examples such as a shower head with prices ranging from $7.87 to $437.22, jewelry organizers from $9 to $109, and orthotics ranging from $99 to $800. There's a little bit more going on with the expensive ones than just being a heap of plastic that you can duplicate at home, I think.