Look at the situation from the viewpoint of the German middle-class in 1930: The Russian Revolution had occurred in 1918, twelve years before. There were ethnic Germans in the Soviet Union, and word was getting back about the purges, exile, and murder of the old middle-classes there. Add to that a rising, militant Communist movement in Germany, and the German middle-class would back ANYBODY who demonstrated a willingness to wade into the streets against the Communist militants and bust some Red heads.
Agreed, and some say that it was planned.
Not only did the Germans see what was happening in the Soviet Union, consider the behavior of the Spartacus Party in Berlin. Curiously, Spartacus was the code name for Adam Weishapt.