It only baffles you because you seem to think that equality of outcome means that any way you slice a cross section, you would get identical results.
That is not the case.
Sure, there may be some cultural reasons as to why some demographics prefer nursing to being a pilot, or being an engineer vs being a businessman.
But there are no cultural reasons as to why one would prefer poverty over not being impoverished, so if you see disparities in the amount of poverty, then a very likely cause is disparities in opportunities.
That is the equality of outcome that we talk about. Preferably as little poverty as possible, even none, if that is achievable.
But, if you see one demographic that tends toward poverty more than another, it is disingenuous to blame that on culture, especially when inequalities of opportunity are obvious to see.
It baffles me that anyone would expect that inequalities in opportunity would not result in inequalities in outcome.
Take the stock market, for example. Give a bunch of people the same amount of money to invest, and they will, by using different strategies and some being luckier than others, not all end up with the same portfolio after 30 years. Some may get ultra-wealthy, and some may bottom out.
However, if you give some people more money to invest in others, then it would be preposterous to expect, on average, those who had less to invest to have as much as those who had more. There may be some who had less to invest who end up with more than those who had more to start, but those will be the exceptions. And to focus on the exceptions is to ignore the bulk of the situation.