They dont really have a choice, the alternative still costs more, its just whether their electorate can realise it.
The Euro was always a suicide pact and now it is a game of chicken.
The thing about the current Greek leadership is that they really don't give a fuck. The austerity programs that the ECB and the IMF demanded have turned the population into a raging mob and if this current group doesn't lift the yoke, they will throw them out and get somebody that will. Unless "Europe" (whatever the fuck that is) is going to put Greece under martial law, the end is already ordained, it just needs to be written.
Europe wanted to punish the Greeks for their fiscal profligacy. History is a bitch, because it was Europe's desire to punish Germany after WWII that led to Weimar which ultimately paved the way for Hitler.