Matter duplication is a tricky problem. Assembling the integral units is already an issue. 3D printers carve matter out of chalk, cardboard, or wax, not a chunk of metal necessary for transmitting energy from the front to the back of a car.
We have the ability to fabricate a plan into a gear or another hunk of metal. Push the AutoCAD specs into a fab. We, as in humanity, also have used robots to assemble those fabricated hunks into a piece of working unit, car, machinery for something else, whatever. This is within a factory, though.
The dynamics, the logistics, of trying to get each unit of material within it's proper place, while being fabricated, have yet to be figured out. It invokes levitation, or, a factory.
It's not going to happen in the basement any time soon, as much as I'd like it.
The government is looking out for it's own interests at all times, just like any organism would. They're not going to "prevent" it, they'll adapt. There will always be government, there will always be churches, there will always be a higher power regardless of how happy each human feels. Humans were built in a structured society. Each person needs a higher power to model themselves after.
tl;dr fuck you