The "don't print guns" laws? What lobby would that be? I actually agree that the US is very vulnerable to lobbying and that 3d printing restrictions are dumb, but I have no idea how you connected the two.
Gun control lobbying groups are pushing for these laws.
https://www.everytown.org/solutions/stop-spread-of-3d-printe...
Basically all of them will throw any other interest under the bus to support their own.
Laws that don’t meaningfully impact alleged 3d printing of guns because you can’t 3d print the metal parts of a gun that are needed to actually do gun things, on the vast majority of devices these laws would restrict.