Pinker is addressing a non-existent audience though. He's trying to be a moderate in a time without a mainstream center. Steven Pinker needs to build a time machine and go back to 1994 before the Bell Curve was published at the very least (25 years ago). The Left is too far gone now. Acknowledging the truth destroys the moral basis of their political agenda. He can't argue the truth, which is that the worst elements of the Alt-Right, the simplistic thinkers who draw bigoted conclusions (in the sense of being closed minded) from limited data, are on par with most of the university and media. The best of the Alt-Right and dissident Right are making arguments on par with the best the Cathedral has to offer. He can't admit that and remain in "polite" university society.
To be a moderate on topics such as race is to destroy the Left as it exists today. Affirmative action is probably net racist against whites and males (you'd have to go back 40 or 50 years to find something as egregious as Google's discriminatory and hostile workplace, and I'm not even sure a similarly clear cut case exists), most institutional racism works against whites and Asians in the education system, the data suggests cops are more likely to shoot at a white suspect. The Left could pursue its current agenda acknowledging these realities, but it lacks a moral component. They could add one, such as charity, but then I can make a charitable argument for working on space colonization "for the good of mankind." The debate shifts greatly in favor of right-wingers. The moral debate moves in the direction of Christianity and decency. If gays aren't being systematically oppressed, the ones doing Pride marches and pushing the teaching of homosexuality are behaving very badly.
The Left also loses a compelling case for community. There's an explicit relationship formed if X owes Y, but if X doesn't owe Y, then X and Y bargain as equals, and if X gets a better offer from Z, then so be it. The Left doesn't offer anything to the other side today. There is no leftist version of the cuckservative. If the Left loses its moral ground, it immediately becomes the immoral actor, the cheater. It needs to make a radical move rightward (towards the center) if it wants to bargain on level ground.
The Left jumped the shark once racism became objectively untrue. "Racists" know "racism" is untrue because they know what is in their heart, but when there isn't data to prove it across society, it is possible for the Left to smear all white males as "racists" and "sexists." When the truth comes out, people are instantly "red pilled" because the Cathedral looks suspiciously anti-white and is clearly telling lies. Totalitarian behavior is logical because it is their only path forward if the idea of secession/decentralization is verboten. Pinker hasn't thought this through to the end, or he knows that forcing the left to open up even a little bit will instantly go from a trickle to a flood, and a moral and cultural revolution against the Left will erupt.