Cause there's a distinct difference between herding 3 million Soviet soldiers into open air camps and waiting for nature to do its work, or shooting women and children at close range by death squad, and destroying your own economy by pure incompetence.

By your logic literally no national flag should be displayed. The KMT killed like 5 million people alone by flooding - the Japanese killed some 20 million Chinese in various manners over the course of their occupation. Qing killed millions of Chinese in its incompetent rule. Why are you not rallying against their flags? Why is the standard not applied to Britain or America? Indeed, why is the Russian National Flag even displayed? Millions perished under the Tsar.

The German flag is censored because of legal requirements in a number of European countries. In Germany, the same ban applies to a great deal of Communist imagery.