There is mismanagement of public money everywhere. There are people who abuse their position of power everywhere. I can agree if someone says it is impractical but to say it is evil is just misplaced anger.
Even if Communism is evil, it is still true that the people orchestrating the red scares were evil as well.
Bending over backwards to defend totalitarian regimes like the Soviets or CCP is obviously grotesque, but this kind of blanket pronouncement is about as nuanced as their thinking.
https://www.marxists.org/subject/frankfurt-school/
And Horkheimer is of course famous for saying, "If you don't want to talk about capitalism then you had better keep quiet about fascism."
Oh, if your just talking about Leninist vanguardism a d it's Stalinist, Maoist, etc. descendants, sure.
But that's not all of post-Marx Communist thought, and its a subset that shares common and fundamental deviations from Marx, and it's been criticized by non-Leninist Communists since day one.
USSR bolshevism was just as evil (or even more so) during their 'new economic policy' (free market capitalism) years.
Revolutions establishing de facto dictatorships were just as evil as any other dictatorships, no matter if their economic policy in the end was communism, fascism or free market.
Revolutions creating a one party communist state were just as evil as revolutions creating a one party theocratic state or one of the many cult-of-personality fascist regimes that happened also long after ww2.
Revolutions or coups establishing oligarchies or committees running everything were, again, just as evil no matter what economic policy they run.
The evil of one group gaining power and slaughtering another group is the same no matter if the "othering" happened because of class warfare, religious hatred or ethnic cleansing.
It's just that in the 20th century communism was the most popular cause of regime changes resulting in such dictatorships and single ruling party systems, though nowhere near the only one.