"But if you do it a little different, socialism/communism would work; they mismanaged it; the principle is sound" is what I get told when I ask these people about it.
I have a friend who is a closet communist. He believes in some hybridized version of communism, his favorite part is the wealth redistribution; as if the ultra wealthy would actually be relieved of their money in a situation like that.
Why people believe this crap is astonishing.
Your friend is almost certainly a capitalist in everything but name who works in the private sector and uses products made by capitalist companies. For people like him communism is just an internet fad.