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.
In order to say something is genetic, you need to rule out confounding factors that apply. For example, twin studies attempt to reduce the effects of upbringing (cultural influences, home stability, access to education and other opportunity). This is effective in things like trying to determine whether there may be a genetic component to homosexuality - for example, there’s a statistically significant likelihood (that doesn’t exist for non-twin siblings) that if one twin is gay, the other one is.
However, you can’t aggregate twin studies of one group (“white people”) and another group (“black people”), since you’re not getting around the underlying confounding factors. So, while such twin studies do find that genetics play a role in academic performance (since if one twin does well, the other is statistically significantly more likely to do well too), it isn’t helpful as a mechanism here.
Anyway, jumping to genetics for things that have clearly more local causes is at best lazy. I don’t doubt there’s some genetic factors out there, but we don’t have an easy way to untangle them from other factors.
But we do have several different studies that show a connection between family income and academic performance (even at the same school), parental education levels and academic performance (ie, generational effects), class sizes (in early education) and academic performance, teacher quality, school funding, and so forth.