I have an acquaintance who is dishonest but dumb. Because she's dumb, she doesn't realize that her lies are transparent. She fools no one.
A similar problem holds for pseudo-leftist activists' and intellectuals' calls to purge academia (especially economics) of past racist influences. They are dishonest but dumb, and no one is fooled.
Now, on Twitter and elsewhere, you see people calling for purging academia of his thought. You see similar calls for purges of other intellectuals on the right or who have some connection to libertarianism, though in the latter cases, these allegations are often fabricated. No one bothers to investigate whether Stigler's views on black work culture in any way affect his peer-reviewed work. He said racist stuff, so therefore everything else he said is suspect.
But here's why this doesn't fool anybody, not even the people doing it: They aren't consistent. They aren't digging up the same dirt on intellectual heroes or influences on the left. They aren't saying we should eliminate the anti-Semitic, racist Marx ("lazy Mexicans")--or all of those he influenced--from the curriculum. They aren't saying we should purge the anti-Semite, eugenicist Keynes. They aren't digging up dirt on left-wing intellectuals from the 1940s and 1960s, though plenty of such dirt is there. They aren't saying we should oppose, say, the minimum wage even though its original purpose was to starve undesirable races. They aren't saying we should oppose progressive politics despite progressivism's heavily eugenist origins. They aren't demanding we purge philosophy despite so many 20th century philosophers expressing sympathy with totalitarianism and gulags. Why not?
Probably it's because they aren't really interested in racism. Anti-racism is simply a cover for a long-standing agenda developed back when their intellectual forbears were all racists. They instead want to push for various socialist political ideas unconnected with race. They recognize there are various economic and philosophical objections to their ideas. Unable to defeat them, they instead look for (and, if they can't find it, invent) dirt from the originators or influences on some of those ideas, and then declare the ideas dead through tainted genesis.
If you offer a principle or a method, but you only use it as a weapon against others while ignoring what it means for your own views, you aren't sincere. It's transparent.
Now, I wouldn't go so far as to claim the people doing this are themselves racist. But, nevertheless, if someone attempts to co-opts people's legitimate concerns about racism for self-serving purposes, that person can't be said to care much about racism.
UPDATE:
Here's an example of Nancy MacLean nodding in agreement with actual, outspoken, explicit racists and eugenicists in the book where she dishonestly tries to smear Buchanan with racism.