I mean, it will eliminate the low bar, but... all you need to do is pull out the SOC controller board, throw in anything with GPIO or heck even a printer port, and the software is easy to write yourself.
And also the cat is out of the bag, rep-rap from 15 years ago anyone? And there are so many ways to walk into a hardware store and buy everything you'd need to create much better firearms than anything a 3d printer could produce.