Because they reckon that they can delay it until 2013, which is estimated as the date when the German banks will have more or less managed to pass their losses to the public (by selling rotten assets at nominal value, mostly).

At least that's been my understanding so far. On top of that indeed, there may be lack of full rationality, or rather of proper evaluation of the situation.
Plus, maybe (I know, that's a long shot) some apologists for neo-liberalism actually believe in their crap.

Earth provides enough to satisfy every man's need, but not every man's greed. Gandhi