Are you justifying racism via economic output? I've seen this line of reasoning go horribly wrong before..
Obviously teaching people how to be productive is good. But what about teaching people to discriminate against others? If we were to argue from principle, I would agree that racism is not a virtue. That said, I don't adhere to principled reasoning 100% of the time and would be happy to help "black girls" code.
And just because I know this is coming: https://news.ycombinator.com/item?id=6976062
A non-black girl/boy comes along and says that they want to participate, too. The black girls/their instructors tell them to piss off because they are not black and a girl to boot? If this is not racist, I don't know what is.
How about a program for any children under a certain age - be they black or not? If they wanted to include more of the under-represented minorities in the program, they could promote it more heavily in the areas where the minorities tend to live/congregate. Such approach would achieve a similar goal without being racist.