Marxism is inherently the punchline of what would be a truly funny joke (loser blows inherited fortune, then hallucinates up a completely unworkable view of economic theory to justify it) if not for all the deaths that have resulted from it.
This is absurd, akin to blaming the Bible for millions of deaths or the Qu'ran... or guns. Theory is inanimate - it is only what is made of it.
The only way you can blame theory is if you can find explicit and undeniable exhortation to commit the deeds in question. This does not exist in pre-Leninist theory any more than the Peter, Paul, Matthew, John (and Ringo) justified the Spanish Inquisition. And for those who don't subscribe to Lenin's theories (or those who came after), it doesn't apply at all. (And really, talking theory, it would only apply to Mao. Stalin was notably devoid of theorizing, Lenin never called for murder even if you want argue he participated in it.)
Regardless, the refrain of so many who adhere to socialist ideals is that "nononono...RussiaRomaniaCubaNorthKoreaEastGermanyEtc. weren't truly examples of my ideology which requires that the means of production cannot be privately ownedblahblahblah."
On its very face this is an example of the "No True Scotsman" logical fallacy.
I know you just discovered a new term and everything, but you might actually look into what that fallacy is and how it relates to accepted and contested definitions.
You might even look into the site where you learned the phrase. Particularly the final paragraph.
Now, if you can find evidence of some form of hidden groupthink, or that what I've said about divisions among 'socialist' ideologies and histories to be untrue, you've got the start of a case.
But you can't, because everything I said is fact.
Would it make you feel better if I were to couch my criticisms of Marxism/Communism/Socialism/Etc. in language imbued with the utmost gravitas?
I'd settle for a lack of willful ignorance.
You don't seem to feel that one can voice valid and reasonable arguments against 'communism' (or socialism or individual ideologies) without simply denying oneself the chance to understand them.
Sometimes I wonder if the desire to understand or the indifference to the same lies in the underlying software of our brains. It's not a left-right issue - I've known lefties who get pissy when you start to question the sources of racism and on the right it seemed that if you had any desire to rebuild the long chain of events that led to 9/11, you were a terrorist symp. Racists are just born wrong or raised wrong, there's no rationale to their feelings. And terrorists are just born evil, out to destroy us all, nothing rational factors into their decisions. I find that viewpoint distressingly simplistic.