Worth pointing out that "bank-issued debit cards" in Germany usually refers to EC Cards, which is not the same as the Visa / Mastercard debit cards the rest of the world is used to. As a tourist in early 2015, international Visa & Mastercards were useless in most supermarkets & department stores - but international chains that get lots of tourists will take them (eg Starbucks, McDonalds, Subway etc).

I love Germany, but the credit card thing drives me nuts. I understand Germans like financial privacy, but I like having an electronic record of my purchases instead of having to write down every cash transaction I make before I forget it. (If there was a way to get a prepaid EC Karte as a tourist, I might not mind so much.)