Greece's problem is that corruption essentially extends to every conceivable part of the society (cab drivers were repeatedly on strike when it was suggested that they should give out receipts), strong left-wing parties who make sure that the populace a) has no basic concept of economics b) is always ready to blame the "capitalists" for all problems in their life c) the politicians realised LONG ago that they can use the people's own money to buy votes from them.
I've lived there for some years, I could write an essay on it. On the plus side, contrary to popular belief, Italy and Spain do not have a monopoly to smoldering hot brunettes. Probably the hottest girl I've dated in my life was Greek. Of course, we also had a 4-floor house in central Athens at the time, and chix dig bux.
Edit: you can't blame the structural issues on the Euro, they essentially go back as far as Byzantium.