I mean, in the the liberal west used violence to replace comunism with a right wing dictatorship. Yes.
However that isn’t really a flaw in comunist theory
Yes. Basically, any time someone tries to do something nice for everyone and introduce communism, some people or other come along and fuck it all up. Then they call their fucked up monstrosity “communism” to further damage the credibility of any meaningful progress.
Those people are the same people who fuck up capitalism and distort it for their benefit. Maybe it’s easier for them to do under capitalism, maybe that’s just what they’re used to and they don’t want to change, but if all you do is deal with capitalism as the problem then you’re still going to have a people problem with whatever comes next.
You call them capitalists because they were successful at fucking up capitalism.