I think the issue is that nobody has expressed an interest in flying the 380 to ATL. A 380 is more of an airplane for airports with very restricted capacity.
MEM is already being upgraded for Fed Ex. They are currently the only US operator with the 380 on order.
The big issues for Concorde in the US were sonic booms and noise.
Seems to me last time I flew in Europe there were plenty of noise requirements there too. And lots of restrictions on who can fly into where and when they can do it.
Not much protectionism here in the US. We are busy exporting factories and importing everything else.