Marx, Darwin and Freud: A Critique-Part 1

We all know that Marxism failed. It's political application in Soviet Union and Eastern Europe met with catastrophic failure. Communism failed as it created classes within class, some higher than the others, and led to financial crises, political chaos and breakdown.
There is another important reason why Marxism failed. Marx propounded his theories in late 19th Century, when the entire Europe was teeming with industrial activity. Among the people of Europe, Marx identified a class: that of workers, millions of them. Similarly, he saw a class of peasants in the hinterland. He believed that both these classes could join forces, and overthrow the whole of bourgeois economic system.
Marx failed to realize that the class comprised of individuals. That each individual was a human entity, born and trained to be different than others. Even in a homogenous environment, each human was likely to show some competitive individualistic traits and attempt to break out of the monolithic institutions. Marx failed because he failed to take his lessons in human psychology.