To be fair, you're incorrectly assuming that anyone who posseses and uses a firearm is carrying-you're also incorrectly assuming that anyone who lawfully carries resides in a state that requires training. "open" carry, that is, carrying without concealment, is legal and requires no training in several southwestern states-at one time, in Arizona it was not at all uncommon (though somewhat unnerving) to see a tribe of bikers ride up with pistols strapped to their leg old-West style. In New Mexico, open carry is pretty much the law (there may be municipalities that restrict it, but I don't know of any) and doesn't require any training.
The U.S. is a big place, and we're not all unfortunate enough to be living in the People's Republic of Massachusettstan...