Where the only people unjustly punished and horribly mistreated are not in fact communists are bullshit.
Do you think the persecution of leftists on a political basis is somehow not wrong? Do you not realize that the anti-racists, feminists and LGBTQ people persecuted were often in fact commies, and is their persecution any less meaningful because they were communists? Is destroying the lives of people because they wanted a world where workers no longer lived under the boot of capital any more just?