That's not racist. It's pragmatic, reasonable, and a good idea. I haven't looked at the figures recently, but some years back over 90% of all automated exploits were coming from just 3 countries. If you don't do business in those 3 countries, blocking them wholesale massively decreases the risk of succumbing to an automated exploit and reduces the sheer noise in your operational workflows so you can focus on things that matter, not script kiddies with fat pipes.
It can also reduce your hosting costs significantly. I do this on every service I personally operate, and I've never once though about the race of the person I'm blocking. In fact, I don't even believe that the IP space being blocked necessarily represents attacks coming from inside that IP space, it could just be exploited systems being used as jump boxes by attackers elsewhere. From my perspective, it doesn't matter, I just don't see any reason to allow attackers to access my sites and services from regions I don't have any reason to serve.
Maybe come up with a better analysis than jumping to "she's racist"? It just makes you sound dumb.