>Socialist critics [during the time of the USSR and others] include George Orwell (known for his criticism of totalitarian Socialism in Animal Farm), economist I.I Rubin, the anarchists which the USSR suppressed, Luxemburg, Bordiga, Bookchin, and later on Hobsbawm, Trotsky (to some extent), Sylvia Pankhurt (and various other feminists) etc.

Furthermore, Communism does not necessarily entail Marxism-Leninism or even Marxism. Do you not think it should be the responsibility of modern day Marxists to find problems with previous attempted implementations, and find ways to fix those problems? Marxism is after all a method of analysis, and can be recursively applied to itself.

Mises is an interesting choice for a 'moral' theory, given the theory of primitive accumulation, property acquired through barbarism, and the exploitative and environmentally damaging nature of capitalism itself, regardless of application. Marx's theory does not rely upon notions of morality, though - it posits merely what is in the interest of the workers themselves. This is why Marx and Engels hoped to advance a scientific theory of Socialism.

Edit: it's also rather comical that the term 'libertarian' was transformed to be about some narrow form of property ownership rather than freedom itself, ironically not realising the tyranny of property and its contrast with the ideas of equality, freedom and justice (Proudhon talks about this in the link in my previous comment). Bookchin and Chomsky have talked about this change, too.