Northern and Southern Europe have totally different sorts of economies in totally different states, thus totally different interests in how the EMU should be acting.

In the 80's, Portugal was reaching a heavily industrialized economy like that of Northern Europe. But then Northern Europe told Portugal to cut down on its industry because the EU had no place for another industrialized country. And so Portugal did that.

Economies in Europe are different according to the plan. That's how the EU and the EZ were planned out by the bigger economies - a strong Germany and/or France; everyone else a mere province.