Of course. Marx was a philosopher, not a statesman. Like Malikane, his ideas are best kept in the realms of academia, philosophy and wishful thinking. But ideas and philosophies can and should be judged by those who have attempted to implement them in the real world. That's the true test of ideas. These countries failed because politicians were so blinded by ideology and became so dogmatic that they refused to learn from history, employed no common sense, sought power and war rather than peace and prosperity, became corrupt and ruthless rather than seeking the common good, and were prepared to sacrifice the lives of the masses for their "revolution". Should Marx be blamed for that? No, but history allows us to put a big fat question mark behind his ideas.
Is John Maynard Keynes to blame for the great depression and the current great recession? Of course not. But his ideas too can be tested by those who implemented them. And we can put a big question mark behind Keynesian economics too.