I would recommend that you re-read some parts/phrases of this thought piece. Professor Wax claims that blacks are not as smart as whites (”cognitive ability”) and that they do not work as hard. Sounds like classic race generalization to me. However, if the requirements for a job include specific job-related testing (a fireman candidate must carry a load of X pounds up three flights of stairs in Y seconds; or a mechanic must be able to solve a certain set of problems in a given time frame), then let the chips fall where they may.
I suggest you look up average IQ scores by race. The distributions overlap, of course, but the means are NOT nearly the same.