The difference is that Dr Kings actions CHANGED lives. People can vote, go to school, eat in restaurants - actually be treated as human beings because of his actions.
MJ was only entertainment. He changed the way people dance? That's it?
And I would say people EVERYWHERE in the world have had indirect benefits of the cicil rights movements. Racism and cultural hatred are certainly less prevelent since the attitudes toward them changed in the 60's. Certainly still lots of problems, but I think we've had major advances in 50 years.