Around Germany and Greece there were other countries. They went by names like frugal four and PIIGS. They forced "austerity" and stricter working hours onto indebted countries to save their own banks.
The colours on this map show well that northern "productivity" is not about working hours, but about other topics that did not get addressed. Among these topics are also tax heavens (think the Netherlands) and money laundering (think Austria's special relationship with Russia).
So it was nothing more than poor political leadership without vision.
They go to work for one half-hour, two half-hour. Then do something cool for lunch like a cigarette, 2-3 bottles of a red wine and a bowl of heavy cream.