Marx was the product of his time. Of course he held the set of values that "some nations are better than others". You still have that attitude in the 21st century in the European Union, the brotherhood of men. You also have it in the US. Why is the American life the best in the world?

No historical character was a saint, nor was he a devil. By studying theese people, we learn about human nature as well. That's why "Historia magistra vitae est." But you can interpret the text and believe whatever you want.