The German language is full of Anglicisms – that is, words or phrases that come straight from English and insert themselves into German. In German it’s known as an Anglizismus, and the habit of incorporating English words into German is called Denglisch (a portmanteau of “Deutsch” and “Englisch”).
Examples include the words “crash” and “reboot” when talking about computers, and these words decline and conjugate like other German words (e.g. “Ich musste den Computer rebooten, weil die Software gecrasht ist” means “I had to reboot the computer because the software crashed”).)
Sometimes the meaning of the original word is changed slightly, for example Germans call their cellphone a “handy”, a TV show host a “showmaster”, and a photoshoot a “shooting”.
While it’s considered a pretty serious swear word in English, the first syllable of this particular word does not have the same stigma attached to it in Germany, so rather than being a coarse term used only in certain situations, the Germans have embraced the word. According to the head of the panel of linguists responsible for making sh*tstorm the Anglicism of the year, Anatol Stefanowitsch, the word is totally acceptable to use in public.
Of course, that doesn’t mean it’s suddenly become a polite term in English…