Are you sure it's not just that your card has both EC and Visa Electron/Mastercard Meastro or similar, and that it's the EC part they accept?

It's been a few years since I've been to Germany, but for comparison, in Norway - while it's nearly unheard of now - you also used to be able to find places that'd take "BankAxept" bank cards, which would be pretty much every domestic debit card, and is similar to EC Karten, but not Visa Electron/Mastercard Maestro debit cards.

If you had a domestic debit card, you'd almost certainly have a Visa/Maestro logo on it as well and so it'd be easy for people to assume that was what they were paying with.

Was travelling through Sassnitz / Rugen last year and the restaurants we visited didn't accept cards. We had to run around late trying to find an ATM the first evening. And that is a tourist region even..

I live in the northern half of Germany and not even the postal office near me accepts Visa. (Let alone the many non-chain shops around me.)

I work in Mitte in Berlin, 30 minutes walk from Brandenburger Tor, and just got lunch from a pizza takeaway in a building that didn't exist 5 years ago.

They only took cash.

Overall it seems more common than when I first moved here, but that's starting from a low bar, I'd guess going from 1/6th to 1/2 of the cafes and restaurants.