No, the availability of cheap parts did.
The 80s and 90s were marked by a distinct downturn in the "maker" movement, or rather, hobbyists who would tinker for fun. You can see it in the magazines - former hobbyist mags started turning into consumer electronics extravaganzas as people cared less about soldering bits together and assembling PCs and doing all sorts of nifty software stuff with them. Interfacing things became a whole lot less interesting.
The 2000s changed all that when people started getting interested in making things for fun again (Arduino had a big hand here, but there was a revival).
And guess what? 3D printers are back because the maker movement has ready access to cheap computing (Arduino, rpi, etc) that talk to computers super-easy (back then, you needed to build an ISA card, deal with DOS, etc, now, you can do with Linux or Windows, talk using USB, etc) and subsequently parts like stepper motors and all that.
It was less patents, and more hobbyists. People were 3D printing in the 80s and 90s, but they were big companies who could afford the equipment, and hobbyists were pretty much left high and dry - either you talked to a PC using ISA or if you were skilled, PCI, because cheap microcontrollers that were very capable were hard to get and even harder to assemble. Then you needed the skills of a mechanical guy to help build the xyz platform. Something the internet made readily available.
So basically the revival of the maker movement or hobbyist tinkerer, coupled with the rapid availability of talent via the Internet (and the availability of parts and supplies - being able to order anything online without it taking 6-8 weeks is a real boon), plus cheap and easily accessible microcontroller platforms that interface to everything make the whole project doable.
Was it doable in the 80s? Yes. Was it easy? Not so much. When you're mail ordering parts because you can't find it locally, having to start, stop because you miss something etc., and then finding someone to help you with parts of it can be challenge.