You think that all of them do it out of knowledge? Remember that if they weren't born before 1980, they've really only experienced the effects of capitalism on their countries. I've heard it happen before, that some 20-25 year old who immigrated with their parents in the mid-2000s is going off about how "communism ruined my country and that's why we had to leave", or something.
In 1991 the referendum to dissolve the USSR was voted against by the population (of course it happened anyway).
I don't mean to suggest that the political or economic systems implemented under communist governments were perfect, or even that great, but in the English-speaking world there is a tendency to assume that everyone (or even a majority of people) who lived there were against their own government, when it's much more complex than that.
A modern example I noticed recently was in this video, where the people living in the warzone in Eastern Ukraine are generally supportive of Russia, and miss the USSR (I mean, if anything, the current conflict never would have happened). Of course these two people don't represent their whole community, but it's more complex than is commonly portrayed (all I'm trying to say).
Watch from around 3:15 till about 20 minutes in when the old guy in the shirt is done talking (or just watch the whole thing idc): https://youtu.be/drhgjxSJG6M?t=197
Sectarianism (which the OP is also guilty of) makes for a dull conversation.
Particularly in the English-speaking world, there is no sect of socialism that has enough political power for that sort of conversation to matter. It's just shit-flinging over the internet. I know that Lemmy has a ton of "Reddit" in it's genes, but my hope is that we can try and build something more interesting here.