Greece doesn't have to crash or die. It just needs to recognize that there's no substitute for economic activity that is productive and not merely paper-pushing or doing useless things. I vote yes for the EU exit. While they may have had some sort of tenable union for some time, they do NOT have the following:
Monetary union - How northern Protestants and southern Catholics in the Union view the use and handling of money is vastly different.
Language Union - There are many different languages spoken in just a single government meeting or function.
Culture Union - How people live, do things, and what they believe in the work-a-day life is different also.
The mistake I believe is in trying to copy the union of the United States when it has these differences that are rooted in thousands of years of history. The situation in the US is very different, with largely English speakers coming to the New World to eventually form the US, and requiring from a hegemonic position the learning of English and culture of the New American.
I think what ought to happen instead is one of two choices at this point.
1) Go back to the way things were post-WWII. Every country has their differences and ought to be honored and respected.
2) Look at India and see how they managed to have a country even though English AND Hindi are both used as official languages in government, and there are many, many languages, customs, and beliefs in India. You can go from one state to another pradesh and think you might be in a different country, but what the unifying thread of India is Dharma. They don't try to stamp out differences in language, culture, and beliefs, but embrace them instead. Unity in diversity.
The western world, in order to grow and move forward, has to move beyond the western style of looking at things, with its competitive "us versus them," exclusive, defensive behaviors and look to cooperative, "let's work together," inclusive behaviors. Right now, western civilization, in comparison, does not have a lot of Inner Science, or Consciousness knowledge to understand what is happening in the big picture (as compared to the Indic or non-Western world that is inclusive, world-respecting, etc.).
Though this is changing in Europe as a result to exposure to India's ways, Europe still has a long way to go, and America has even further to go.
Just my opinion here...