I dont think there are enough gun owners that care enough to not comply. I think the majority are fine with registering their guns.Exactly my point. I haven't seen the Denver ordinance, and I haven't seen the proposed ATF rules - yet. The devil will be in the details.
I would not be surprised if the intended end result is registration of all guns in our possession, regardless of who manufactured them. At which point it will come down to a matter of compliance.