Given in your scenario the US govt has just destroyed the dollar (due to excessive printing) and wiped out trillions of dollars held by bond holders WTF would I want to purchase a coin where they are in control of the printing?
It is like saying you have some gold coins and someone is selling turds. Would you trade your gold coins for turds? Um ... no.
What if the vast majority of the public went with it?
USCoin would get the publicity, the acceptance and the volume that Bitcoin can't.
So basically the Gov is going to tell the public:"USD is in trouble! It's in such big trouble that i have to make a Bitcoin copycat, better run from it as soon as possible!"?