Race is an incredibly sensitive topic in America. The best analogy I can come up with for the author's statement is this:
You're looking to pick the fastest runners out of a group of people. You run an optimization algorithm to pick out the fastest in that group. Nothing about this optimization accounts for the fact that 1/3 of the people in the group have been being shot in the foot with a gun prior to your optimization. The data will show that they are poor runners without addressing the crime previously committed. In fact, many people would consider it a second act of crime.
You're looking to pick the fastest runners out of a group of people. You run an optimization algorithm to pick out the fastest in that group. Nothing about this optimization accounts for the fact that 1/3 of the people in the group have been being shot in the foot with a gun prior to your optimization. The data will show that they are poor runners without addressing the crime previously committed. In fact, many people would consider it a second act of crime.