Moving bankers bad investments onto public books is a monumentally poor decision for everyone, and the effects of the decision should be undone.
However, if France and Germany have no appetite for holding their bankers responsible for their poor investments, and if they can honestly convince their citizens to pay for the bankers poor investments, then that is a (poor) decision they can make (and have so far made). The better decision is to require repayment of bonusses, let the losses materially affect banks shareprices, and let bank-shareholders lawsuits handle the rest.
On the other side, pushing the financial burden of a bankers bailout onto the greeks is counterproductive to everyone (who is not a banker) in the eurozone, and is morally disgusting.