What if you go to the roof of a building and take a photo of a crowd on the street below? Do you need to get everyone's permission to publish that? What if you can't even recognize their faces from that distance? This law seems impractical, unless there's exceptions noted in the text of the law itself.
Crowds and persons insignificant/incidental to the image composition, as well as "newsworthy events" (e.g. a politician speaking in their function) are mostly exempt, so all of these examples are not a problem, practically.
Given that the parent was claiming that you're not even allowed to take a photo of somebody in public in Germany, I think the salient point here is "you actually can, unless you publish it", and it's less relevant that you can also publish it in many of these cases.
