Academic and scientific bodies (universities, groups, etc) decide something is taboo and ignore it. Meanwhile the proponents keep talking about it, keep building it, keep it alive until something magical happens: social media arrives, and perhaps more importantly Elon Musk (a Boer racist) buys Twitter. Race science has always been around in America but you could argue it has become far more discussed and propagated since Elon bought twitter. Now a relatively normal person with normal views can be exposed to various weird racial IQ profiles on twitter. And if you click them one time, it gets added to your algorithm going forward. These are rabbit holes of indoctrination and extremism that are being deliberately spread by Elon.
I think Will Stancil is correct that liberals have spent a lot of time ignoring these things instead of confronting them. Now to be fair, I understand arguments about platforming. It's why I simply refuse to engage with people who are engagement/hate farming or being disingenuous, like Candace Owens. But this is something else entirely. If Stancil, who is basically just a random policy nerd on twitter, can easily manhandle these weirdo racists intellectually, how hard would it be for actual academics to dunk on this stuff in an academic setting? This should have been done 20 years ago. Frankly even longer, it should have been done when the Bell Curve book came out in the mid 90s. Instead it wasn't confronted properly, academics started ignoring it and here we are today.