It was like letting a bank fail without having a proper mechanism for managing this failure, as it had happened with Lehman. Now, to be fair again, one has to address another side of this. The lack of fiscal discipline by certain countries was perceived by other countries as a breach of the trust that should underlie the euro.
Formal econometric exercises confirm this observation and suggest that the wage-inflation pass-through is state-dependent. One finding is that the pass-through depends on the type of 2/3  BIS central bankers' speeches  shock hitting the economy: it is stronger for demand shocks, and weaker for supply shocks.