I'm not sure that I see the reason for all the excitement. Basically, this is a new manufacturing method for producing a makeshift firearm from otherwise easily available materials. This isn't even a particularly good gun, since it appears to only be usable for a single shot.
Simple, easily manufacturable guns have been around for quite some time. One of the more interesting historical examples is the Sten gun manufactured in small, improvised machine shops during the Battle of Britain after the British army lost a significant portion of its armory during the Dunkirk evacuation.
This is not the revolution in gun availability that is being proclaimed by gun nuts nor is it the catastrophe that is feared by gun control advocates. It is just another improvised firearm, like those that have been available for a very long time.