Of course not all Germans go for lunch at 12-1 but unless you are in retail or your team has decided 1-2 is better, or 30min is enough.. I think it's just a very good guess that it's 12-1 for most the people. If it was a real 50:50 split between 12-1 or 1-2 then it could look like a 2h break. Unsure, I can't read their data properly.
But they do? At least near us? Shops close from 1 ‘til 4, and are then open until 9pm. Some businesses like mechanics too - although offices tend to stick to the more widespread 9-5, with more lunch from 12:30 to 14:00.
It's "funny" how someone that is supposed to be so smart, can be so ignorant at the same time