I believe such forces are the indirect result of the structure of society and economy.

If legal arms dealers want the state to step in because of some decentralizing technology, then for the government it would be yet another cost center to combat this phenomenon. So lobbyists need to come up with a kind of reward, and design more "palatable" proposals, so that income can be derived by somehow initiating government control into the whole decentralized technology instead of just the illegitimately decentralized subsection...

but punishing "the rest" for actions of a few would mean financing it with taxes, instead of scapegoating the legitimate majority of 3D printer users.