So you are saying Greece lied, therefore the fault isn't with Greece, it's with the other EU countries? You're making my head hurt.
There's a difference, and an important one, between 'fault' in the moral, blame-attached-for-wrongdoing sense and 'fault' in the 'error, mistake, deviation from correct operation' sense.
You know the saying "If I owe you $1000, I have a problem. If I owe you $1,000,000, you have a problem."? It's not that Greece's government is somehow the morally blameless party; but it's the eurozone who is revealed, by Greece's failure, as having been...'optimistic'...about its due diligence in the past; and apparently without a coherent plan for what to do if that comes back to bite them.
It's not entirely unlike the US mortgage fuckup: sure, you can scold the irresponsible borrowers, taking out those loans they can't afford; but it's the lenders who have a giant pile of bad loans on their books, a strong suspicion of insufficient scrutiny in their past dealings; and no terribly coherent plan to do anything about it. Greece is unlikely to enjoy the experience; but countries defaulting is a thing that happens from time to time. For the euro, though, this is new territory; and potentially not the last country they'll have to do some variant of this to. So far, they aren't showing all that much promise.