University of California was wrong to eliminate the SAT

So argues an emeritus professor of economics at UC Santa Cruz.  He certainly makes some good and well-supported points, but I had two doubts:  (1)  the real worry about the supposed "bias" of the SAT against lower socioeconomic-status students is that they get lower scores (perhaps because they cannot afford exam prep courses) so don't even get admitted, not how they perform once admitted compared to higher socioeconomic status students; and (2) one suspects the real motivation for the change has nothing to do with socioeconmic status, but rather race and ethnicity (African-Americans and Hispanics get lower SAT scores on average compared to whites and Asians), which can't, however, be the official consideration given California law.