I'm no fan of fiat, but your statement is tautological at best: the fiat currencies that have collapsed, collapsed. Communications tech and electronic fiat make the future anyone's bet.
The problem sounds like the debts, not the gold. Since, if you accept the debt deflation hypothesis and the idea of debt overhangs, these obviously occur in fiat money systems as well. Gold makes it hard to inflate monetarily, but we observe that catastrophic debts still occur in its absence.
The problems faced by Greece are from a lack of monetary sovereignty, but to equate it as somehow being like a gold standard simply on locus of control alone sounds more like a political talking point than anything else.
Catastrophic debts occur in its absence, but fiat money gives a way to handle catastrophic debt in ways that are a lot less harmful than when it happens in a gold based system.
