Whether or not we tend to lean to toward capitalism or socialism, can we all agree that Karl Marx was a complete failure as a human being?
I don't know too much about Marx as a person. What I do know leads me to conclude that he was a miserable, pathetic man, but that's all really. That said, however, I believe his ideas can be judged on their own merits.
Do you know any non-miserable communists and or leftists? :) It's amazing to me how they can get out of bed in the morning considering how awful their view of the world is. Remember, if there weren't "economic disparities", "social injustice", unwanted pregnancies, violent gun crime, unemployment, etc, then the left wouldn't have a platform to stand on.
As for Marx's ideas, I'm of the opinion that they have no basis in economic reality, and in fact proponents of socialism and communism count on the ignorance of the populace they're foisted upon.