As this Guardian opinion piece by Susan Campbell illustrates, Americans already operate under austerity. "One hand tied behind our back," is our baseline. Some of the hardships and sacrifices Greece is being forced to accept have been commonplace in the US for over 40 years.
And what's so frustrating is that millions of Americans believe the "if you work hard enough" fairyland talk. It certainly doesn't help that we are generally such an ill-informed public. Even when some are enlightened enough to more or less understand, the resentment factor kicks in from the "we are paying for them" crowd. The fact that WE could easily become THEM doesn't register.