TARGET2 is only a mirror of the underlying economic and financial imbalances: with a properly functioning interbank market, no claim would appear in TARGET2, and the underlying economic situation would be exactly the same. Constraining the flow of funds through TARGET2 would address a symptom of the crisis without tackling its causes.
It would hamper the freedom of capital movements as well as the smooth operation of payment systems, which is a basic task of the Eurosystem as mandated by its Statute. The current situation is not a viable risk-sharing arrangement for the long run.