This is why the EU is a stupid idea. When it is the south, they should suffer, when it is Central Europe, everyone should come together and sing kumbaya
Anecdotal: My dentist was from Rumenia. I'm sure they need dentists too but he can make more money in the Netherlands.
is the cultural problem an important factor? as someone who's also from the south, yes, i think it is. is it the only one (that matters)? no.
the eu (and the euro) works mainly to provide a cheap-access market for the stronger economies to a series of other countries. it's extremely difficult for poorer economies to compete with the stronger ones (due to regulations, size and how those two interplay). it's even more difficult for those economies to provide the same quality of life (i.e. higher salaries, same level of social care, etc.) when they themselves don't have full control of their economy/market.
That is totally to forgot that Italy has been cost reduction/ austerity since the 90's. Precisely when it's started to do that, its economy stalled.
Spain had its debt going from 30% to 70% after the 2008 crisis.
Even in Germany, parts that lost industries decades ago are still borer that the rest of country. France and Belgium have similar problems and Italy north-south split is even older.
Nobody know how to reverse it or at least succeeded. This is not easy.
There are pending issues related to management, but also north-enforced market control (milk cuotas come to mind) that definitely have affected the economy.
I really wish the south acted like the north is acting now when Germany was considered the sick part of Europe in the 90s. We would have avoided so much trouble.
The euro just cannot work in the long run. The sooner people up top admit this the better for 300m europeans. But they will never admit defeat.