Well, those countries don't have economies that are even remotely competitive or sustainable. You can't have a society where the government is doing the lions share of spending. It just doesn't work. In the case of Greece, they had what? half of the people working for the government? On top of that they have a ridiculous retirement system.
As I've said before, in the past, the way these countries would get out of their debt was to simply inflate their way out of it. Everyone on a fixed pension would be completely fucked, but it would lower their costs. They can't do that when they're under a common currency, and there's no way they can politically make the reforms they need to make to become more in line with their competition. When they try to reform and make cuts there's a backlash and you end up with morons like Hollande in power. The Euro is going to collapse, there's simply no way around it. The welfare state is too ingrained in the culture of the PIGS at this point for them to ever make serious reforms. People don't want to lose their cushy government jobs and won't give them up without a fight, or a revolution.
At this point Germany is stuck between a rock and a hard place. If they exit the Euro and force a collapse, their debts will be inflated to nothing by the debtor nations. If they try to remain in the Euro, they're going to have to perpetually bail out the welfare-state nations. As much as I despise what they did to Cypriots yesterday, I can understand it from the German point of view: they're tired of the bailouts, they keep dumping billions into the PIGS for no return whatsoever. Ultimately, I have zero sympathy for the German bondholders, because there is not, nor should there ever be, anything akin to a risk-free investment.
"Ah, you miserable creatures! You who think that you are so great! You who judge humanity to be so small! You who wish to reform everything! Why don't you reform yourselves? That task would be sufficient enough."
-Frederick Bastiat
