Quote: "People say that 3D printers will take off, but I think that the first time I heard of them was about 6 years ago. If you were the inventor of a 3D printer, or the creator of one, you make far more money printing 3D plastics for customers than selling your product. It's like someone inventing a Lottery Predictor.. why sell it? If you do sell it, you have to sell it at a price that covers the losses of your plastic printing industry."
Someone probably said exactly the same thing about a 2D printer many years ago.
The only reason 3D printers aren't mainstream at the moment is cost, size and technology. Much like the earliest computers, they can only become mainstream when the cost goes down and the size become compact enough to sell.
Also in their current state, only the very high end 3D printers (like the one in Josh's video) are really capable of producing prints of a usable quality.
If 3D printer companies did as you said, then you've defeated the point of a 3D printer. You might as well stick to traditional manufacturing processes (which are much quicker and far more cost effective).
The point of personal 3D printers is to remove the cost overhead of all the processes that occur after the raw materials have been turned into a finished product (packaging, shipping etc).
All you would pay for with a personal 3D printer is the material cost and also a design fee.
It could also one day create an unusual situation where people could pirate a physical product.