Well I think it is… most of the time… and I AM german xD
But the image that most non-Germans have of the German language is Hitler screaming his speeches out to soldiers, which they get from a lot of WWII movies/historical footage, but they don’t listen to German music or watch German TV or movies, all which give perfectly reasonable examples of German where it’s not being shouted violently.
It’s like as soon as a velar fricative is introduced everyone thinks the only type of speech involved is violent hissing.
While it does have the ability to be a very harsh language, so does every other language. It all depends on how you say the words, not the general construction of the language itself.