There seem to be strong opinions about that. Piranha Bytes is know for their "Ruhr-Pott"-Language in the games, which is an area around Cologne, associated with coal workers and whatnot, so there is a lot of swearing and "blunt" language, at least in the German version. To me that's still very "light" compared to something in a more modern setting from the US where every second sentence includes f*** (think Cyberpunk, GTA...).
But even in the German version, some people don't like it, others celebrate the language. I guess I would count myself to the latter. It's rough, but not obscene.
The two people you are following around are somewhat funny but I think they might be some of the worst voice acting (at least in the german version).
If you are at that point, try to join the Berserkers (and just reload after that) the "ceremony" there is quite funny.
But this is actually an interesting topic. The native and more natural German swearing (not by modern "kids" strongly influenced by the US and ghetto language but more like people born in the last century) is quite different to the US swearing. And when US games are localized to German, they usually just translate it 1 to 1, which in German sounds over the top vulgar quite often, while the "natural" swearing like here is somewhat...refreshing.