No, I'm not presuming this at all. There are countless examples of black people being wildly successful and even more of them building happy, comfortable lives for themselves. It would be very strange if I was suggesting that slavery or Jim Crow doomed all black people to fail. The quiestion is, what was required of you to achieve the same level of success? What obstacles were placed in your path that weren't placed in anybody else's path?
Your anecdote, as inspiring as it is, relies on a society that allowed you to succeed. One that doesn't bar you from opportunity or work or homeownership. A mere 60 years ago, that was the reality for pretty much all African Americans. Some succeeded DESPITE that, but to hold the minority who were exceptional or lucky enough to overcome the huge odds against them, over the majority who were every bit as capable as their white peers but were denied the same opportunities seems clearly unreasonable.
It's also worth bearing in mind that the vast majority of black people don't benefit from diversity programmes or affirmative action. In fact, the overwhelming majority don't. We're not talking about reparations here. We're talking about a small nudge towards justice in response to decades of consistent, painfully clear, systematic marginalisation.
So while I'd agree that anybody (or at least the vast majority) claiming that their skin colour is holding them back TODAY is wrong (I was fairly explicit about that in the article), if you think this has ALWAYS been the case, you haven't been paying attention. In addition, for almost everybody, the success of their parents and grandparents played a huge but easily overlooked role in their success. Things as simple as a stable environment with parents who weren't working 3 jobs or weren't constantly financially stressed.
I could go on and on, but hopefully that makes the point. In short, no, I'm not presuming that people can't change their stars (or pull themselves up by their bootstraps to put it more plainly), I'm saying that some had almost unfathomably worse stars than others, for no reason other than their tan.