> I don't think authoritarian tactics like that, while effective, would fly in the US.

Much of this hinges on how it's done. First, you can't take away rights unless there's a compelling governmental interest. This interest clearly exists; however, it still doesn't fly UNLESS you restrict rights by the least restrictive means possible.

By trying voluntary restrictions first, they can demonstrate that these lesser restrictions were ineffective, and then successfully defend the more aggressive mandates in court if necessary, later.