I'm not sure what point you're trying to make, other that every country does bad stuff sometimes. I'm not debating the fact that the European (and other) empires did awful things, particularly pre-1900. But by 1930, the boundaries of what was considered acceptable by democratic western populations had changed enormously.
And it was the Belgians in the Congo, not the Dutch. And they were truly dreadful, but even there, by 1930, things had improved enormously.
By the late1930s, Britain was just starting to consider the eventual independence of many constituent countries of the British Empire. And rule in many parts of that Empire relied on a large degree of co-option and consent. Also by the 1930s, within Britain there were restrictions on the hours that could be worked and so on. We had universal suffrage. We didn't have vast prison camps housing political dissidents or various types of people considered undesirable.
And I most definitely do not need educating about what the Japanese got up before and during World War II: I grew up on those stories, because they resulted in the deaths of several of my relatives, and the torture and starvation of many others.
The issue with Stalin's Russia was multi-faceted:
- There was an agreement during World War II that the Allies would not take the opportunity for territorial aggrandisement. This meant that even when you had a population within a state that been linked to the Axis, that was actually quite keen to become, at least for a time, a part of the British Empire (as a route to eventual independence), like the Malays in southern Thailand, this had to be refused. Stalin, however, used WWII to wipe out the political opposition in the countries in the Soviet-controlled zone in Eastern Europe and instal puppet governments, essentially turning those countries into client states. Take a look at what happened to Imre Nagy.
- Russia was not (and never has been) a democracy. Under Stalin, it was a brutally repressive state, and ordinary Russians arguably had less freedom to criticise their own government than did subjects of the British Empire. People could be sent to labour camps for extremely long terms for relatively minor infractions (or none).
- Stalin treated his POWs and surrendered enemy personnel appallingly. The vast, vast majority of German POWs in British hands were safely home by early 1948. Over a third of the 3 million German soldiers who fell into Soviet hand, most of them in the final year of the war, did not make it home - even the NKVD admitted that about 14% died in their hands.
The reason that many people are deeply suspicious of communism is that wherever it is tried, it leads to political repression. Russian, Cuba, China, North Korea... Awful stuff happens under many other governments (theocracies and monarchies in particular), but it doesn't seem to be quite as inevitable as it is under communism.
The fact that the Russians also celebrate VE Day doesn't stop me doing so, though for the reasons given above, VJ Day is more significant to me.