Communism, though many would say was a despotic and totalitarian regime which held much of the world back for a century, is still a very defining ideology - cmon, if one nation manages to defy the entire world from 1917-90ish, surely that is worthy of some recognition. It probably was an experiment, if we look at the big picture - humans can't really consider themselves to be all equal: evolution tells us we aren't all equal.
What would the world be like without communism anyway? Less democratic, still imperial, and there would be far fewer countries on the map. Man might not set foot on the moon (if you share the belief that he did in '69), and we wouldn't be able to make fun of an old bearded man in Cuba (although Cubans may not be able to themselves).