If black kids are scoring one standard deviation lower than white kids on IQ tests, it would be useful to know if the cause is something we can do something about (culture, instruction, etc.) or something we can't do something about (genetics) because if we make the wrong assumption, the policies inacted will, at best, be useless and, at worst, be racist. You can't do that if the entire subject area is considered off limits.
For the record, I don't believe that average IQ differences between blacks and whites as populations are genetic. I do think they are cultural and/or environmental. Perhaps that's why I don't fear such research, so long as it's done properly. I can see great value in demonstrating that IQ and achievement differences between the races is cultural rather than simply assuming it and declaring the subject off limits. That only makes the real racists think that science has something to hide. Basically, I think that such research could provide a fatal blow to some racist ideas that have been carried forward from those early days of measuring skulls.