The answer lies in remembering that the West is unique in history being the only civilization to ever identify the ownership of human beings as categorically wrong, and then write that principle permanently into law.

It was the enlightenment values of the West which created the moral impetus for the abolition of slavery, the ending of Jim Crow, and the mere fact that we actively discuss issues of social justice, and how it relates to the historically disadvantaged.

We have to make a distinction between the hypocricy of individuals (slave-owners for instance), and the fundamental values of a society.

A great example of parsing those things out was the I have a Dream Speech. King made no bones about criticizing America which he said had written "the negro" a "bad check." But he was passionate in his defense of the words of the Declaration of Independence, and the values that Jefferson articulated within it.