As far as I am informed one of the rules of the free market is that gains are mine as well as losses. Ergo I have to take losses into account if I flush my money down the toilet and throw it at unsolid offers like the greek promise for high interest revenues. The point is that banks and "speculators" have been doing precisely the opposite. Trying to keep their gains while firstly raising interest rates on Greece to the point of governements having to become involved and then whine loud enough to put the burden for the mess they helped creating on the european taxpayer( along with their willing, incompetent, greedy and corrupt helpers in the ruling greek business elites and governement. Forcing the private sector to become involved is re-applying the normal rules of an orderly economy. If banks invest in risky businesses that go bancrupt they have to write off losses as well in the US I assume.
The rating agency Moodys does not share your opinion as well by the way. While it has downgraded Greece it sees the overall impact and the outlook for Greece as better now : Moody's downgrades Greece to near-default - FINANCE - FRANCE 24