To be clear: Mattarella said no to Savona but would have accepted one of Lega's main politicians as Finance Minister.
The point is that Lega and M5S wanted to break up from the euro while not having said it publicly one single time.
If a country aspired to create an export-oriented economy with large trade surpluses it would, in general, face the severe headwind of rising currencies that made its exports more expensive abroad while lowering the costs of imported goods. That assumes currencies float. If they didn't, the headwind would be less severe.
The Euro is a glorified fixed-exchange regime amongst the European states.
In the real world, that aspiring state is Germany, and that export policy is succeeding spectacularly as the folks in Greece can attest.
Devaluation is the answer, and, leaving the Euro is the only path to devaluation. Otherwise, teaching German, English, and Dutch in primary school is the best hope Italian children have for a better life.