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.
Because the yellow press correctly figured they could sell "we are much better than those lazy foreigners". Nothing more, nothing less. As long as the average Bild reader gets to feel superior, all is well.