If the fiscal situation in one country is unsustainable, this implies repercussions for the monetary union as a whole. Moreover, abandoning the national currency in favour of a single currency has two major implications. First, member states cannot regain lost price competitiveness by depreciating their currency against their trading partners’ currencies and internal devaluation as a substitute is much more painful.
Any institution has, and in any case, should have a character, culture and interest that are worth pursuing even if they appear to be at variance from the sum of the interests of the individual, or the minority or the majority stakeholders.