The fallacy in your comment is that you assume the degraded state to be inherent. I'm Irish myself and while Ireland became independent of its colonial oppressor and is a fairly prosperous nation today, people used to make the same assumptions about racial degradation and so on that you do about black people.

Your argument proceeds like this: Group X is badly off, because group X is inferior, therefore it's group X's own fault. Well, if you knew a group was at an enormous starting disadvantage in an iterated economic competition, naturally you would expect its position to decline over time. But if you were to provide group X with resources to mitigate its disadvantage, why would you not expect it to revert to the mean? On the other hand, give me a license to systematically oppress any group - people in your family tree, for example - and after a few decades I'll be able to make them underperform significantly, especially if operating the machinery of oppression allows me to collect economic rents.