The fundamental reason that their are fewer Black people working in computing as that they score at the very bottom for Math in the SAT:
https://i1.wp.com/www.brookings.edu/wp-content/uploads/2017/...
And the explanation for that is probably deep in history and DNA: Africa as a continent has forever been far less developed than any other region, yielding no overall selective pressure for any of the traits which today produce high Math scores.
Here’s an article from the institution whose graph you reference about why this gap exists - https://www.brookings.edu/articles/unequal-opportunity-race-... - which explains that many of the differences in education available. Black children are more likely to go to schools that have less funding, offer fewer advanced classes, have more students in them, and have lower-qualified teachers. And experiments that involved children going to better schools showed they had better outcomes.
So, yeah, let’s control for things we actually know affects these outcomes first before jumping to genetic factors.