“+ the doctrine of stalinism was based on public ownership + complete lack of entrepreneurship which in fact was one of the main reasons for the collapse of the system” and the other was based on Racism and murdering population not for what they thought but for what they were.
And Hitler as well killed for political reasons and as Stalin. The first concentration camps were built for the German opponents. He evens slaughtered in his own side (SA)…

By the way, the actual collapse is due to so-called entrepreneurs and their greed… So not really a valid reason to condemn Stalinism / Communism…

The fact is most of the reproaches towards Stalin (deportation, forced labours, Secret Police, political coup, absence of remorse and paranoia… etc) were actively done by the Capitalist states…

Communism didn’t work. But that is the only real difference with the Capitalism which is able to reinvent itself…