I am not sure but it should be.In the center of Vienna there is Bitcoin House a small bitcoin exchange there.Vienna is in Austria but most of the laws are almost the same in Germany and Austria.For the moment I havent heard anything calling bitcoin and cryptos as illegal in Germany.
OP is probably from germany and knows the people out there better than us here. This is why he made the speculation of sudden market to gambling casino in their place. Well it could be true for all I know gamblera are anywhere around the world and Germany has it too. I think germany is known in betting for biking race. There are current events on biking that being held in germany. I will stand corrected because I am not too sure too in regards to gambling activity of german people. However I am pretty sure Hitler is from Germany.