Comrade, you must understand the context of these events in the USSR.

I recommend you read History of the Communist Party of the Soviet Union for a little understanding of the situation behind the decisions, the errors, and the correct decisions.

You can’t denounce a whole society of millions of people just because a family member of yours was shot. Actually, considering this society provided a good life for millions of people and your father was considered an enemy is something to be thought of.

It’s true though, that Yezhov, the German spy, was in charge of much of the killings in the Great Purge and when Yezhov himself was shot at request by the Central Comittee of the CPSU, including Stalin, and this event coincides with the period of end of the purges, which really makes me believe the purging was a result of capitalist infiltration in the context of war against Nazism and Yezhov had a big role in it.

So if you want to blame the killings you should research to blame the right enemies, not leaders of the working class.