I think the bulk of the population- even NAMs- believes in HBD. The policy of professed human neurological uniformity (or HNU to borrow Moldbug’s shorthand for the opposite) is pursued as a matter of social peace, and as a matter of self-esteem for NAMs. People are afraid that social chaos would result.
The anonymity of the internet is an aide, but also a handicap. The fact that you can say what you want, anonymously, only underscores the fact that you’d better not say it openly. Of course anybody who discussses it openly is vilified and marginalized.
HBD will be accepted when the people who control public discourse decide it should be accepted.