Groups of people do bad things all the time. If that group happens to be a protected class you simply can't criticize them w/o fear of this.
What would be racist is if he said "since they are brown, then..." But that isn't what the user said.
Not long ago in human history witch hunts swept across Europe and eventually to America. It was no small thing: millions of innocents were either murdered, tortured or imprisoned... And for what? Better to forget this history about humans exhibiting troubling psychology such as this... You might get labelled a witch yourself, or a Jew, or a racist.
To be fair, we are progressing a lot at least in the sense that racism is actually a real phenomenon, and an undesirable one, but beyond that the witch hunt psychology is part of the same thread through history.