What history has shown us is somewhat weaker than you say — for all the stuff they did badly, for all that they wildly missed their own raison d'être and became just another power structure for just another bunch of essentially aristocrats, it did also get Russia from the Tzars to orbit in 40 years.

But that aside, when you're already getting failed and the people failing you specifically hate one thing, it's very easy to reach for that thing.

To your quote: Well, I'm not a communist (unlike a previous partner)… but I'm also not a capitalist, because I see that capitalism also is a deeply flawed ideology doomed to catastrophic failure and devastating results, and that history has shown us this, too, repeatedly.

I'm also not "anti-" either of them, because I'd rather see someone take the best of both and find some new mechanism to deal with the other repeatedly observed historical fact: that a non-trivial fraction of the population are power-hungry sadistic arses. To quote, albeit from fiction: "To summarize: it is a well-known fact that those people who must want to rule people are, ipso facto, those least suited to do it. To summarize the summary: anyone who is capable of getting themselves made President should on no account be allowed to do the job." - https://www.goodreads.com/quotes/2416-the-major-problem-mdas...

(Both capitalism and communism have failure modes separate from the problem of dark triad personalities, but both sets are much easier to deal with if your society has also solved the problem of dark triad personalities, and a society does also need to solve the problem of dark triad personalities irregardless of what else it does).

Good thing when people "support communism" they're not calling for a specific system like the Soviet Union, but just for a higher adoption rate of the good things that fall under the umbrella term.