Real world examples such as economies tanking under Communism and how its leaders are single-handedly responsible for more deaths than anything else in our generation (see "The Black Book of Communism") -- are all ignored because they, apparently, do not represent real Communism.
Perfect Communism, if you will.
Often times, Communists will query "Can you name a country that has perfectly implemented Communism?" As if to divorce itself from the millions of people who have died and suffered under this "benevolent" idea. It's a form of plausible deniability.
The problem with their argument is: It's retarded.
It presumes that all other forms of government have been perfectly implemented. It presumes that Capitalism has been perfectly implemented (when facts show that the only times Capitalism has tanked is due to government expenditure, which is diametrically opposed to the theory of Capitalism.)
So, my question to people who posit this query is: When has Capitalism ever been perfectly implemented? How come even though it's never been perfectly implemented, it still works in every country it's implemented in? How come countries like Estonia that moved away from Communism into Capitalism have all seen positive changes in per capita GDP, life expectancy, diversified employment, innovation, and yes, even the environment?
Get back to me about your Utopia when you can explain that discrepancy.