If this were a case of leders screwing over the people by having governments re-write laws (see: student loans) perhaps more sympathy would be in order.
This is a case where the borrowers have tried to disregard US law, in its entirety.
In that respect, I'm not sure there is anything bad to imply about the hedge funds who simply made bets on the integrity of US Law.
The president of Argentina obviously has her own view and interest at stake, as well.