I believe the primary reason is that skin color is not easily parsed against the majority, dominant cultural norms. It is no surprise that people who grew up with or under those majority norms found success, regardless of skin color. Those who insist their skin color is a factor tend to be enamored by their own exceptionalism rather than focus on their structural or personal failings. That, again, includes any skin color.

This emphasis on skin color as a determinant has decreasing value over time - as it should if things have improved. Recognizing this might be difficult, especially for those whose legacy frameworks were defined by now-distant generations.