Marx was a racist, so were the rest of the dictators.
marx was a political writer, he never held any political position, let alone ruled a nation, how can you say he was a dictator?
I also think that comparing Marx, Stalin, Hitler, and Mussolini is very short sighted. If you want to boil it down and call them all dictators (other than marx) that would be fair, but they way that they ran the political and economic systems were totally different. As LBP said, it's not just black or white. If you want to define communism or socialism as a system where the government is involved in currency exchange, then every government in the world is communist. that is too narrow of a definition and ignores all the other factors that work within different societies.