These nation-specific characteristics in Europe have long history... France was an earlyish adopter of debit-card payments with handheld terminals, while in Germany any form of card payment was relatively rare until the early 90s and actual credit cards were very uncommon for an average consumer for much longer (richer people had the EuroCard, a Mastercard IIRC, but that was about it). Even ten years ago (I don't know now), many non-retail payments (and online shopping) were done using bank transfers (there were (are?) even terminals for doing this in the ATM foyer of many banks).
Some of this might have had to do with fragmentation in the banking system. France seems to have had far fewer small banks, while Germany had numerous very small local banks with little unified communication.
But on the other hand, you have almost no difficulty using foreign cards now in Germany (in my experience), yet you can still have occasional problems in France (mostly petrol stations). And then there's Switzerland where for the longest time anything foreign had almost no chance of working...