"The Bell Curve" is from 1994, a time when the importance of demand for education and skills as a driver for inequality was far less clear than it is today. The real focus of that book was not to drive any racist message, but simply to sound the alarm about how the already extant divergence in educational outcomes would only become more and more relevant in the future unless something radically effective was done to try and mitigate it. People really like to misrepresent that book for some reason, but if anything its real message has only become stronger and more relevant since then.
To be clear, I do of course agree that the book had plenty of major flaws, including in its statistical arguments about the importance of "I.Q." specifically (or of some entirely hypothetical "general factor", whatever that might mean - a "factor" being merely a way of summarizing correlations across measurements, as opposed to anything causally relevant in any underlying model) to outcomes, and even about its observed distribution across US conventional race groups. Much of it would not stand up to even the lightest scrutiny nowadays. But its more general argument about the emergence of a "cognitive elite" on one side, and a "custodial state" on the other, might as well be called conventional wisdom today. These simply were not commonly-acknowledged facts in the mid-1990s!
I don't think this is an accurate depiction of the book (at the time or now). One of the core, repeated messages of the book is that there are no mitigations possible even in theory and we should stop wasting money on trying to educate poor people as there was no way that it would help.†
This is both factually and logically unsound, as well as ethically dubious even before you get into the totally pseudoscientific race angle that was used to sell these political policies to gullible racists.
†Not coincidentally, the Rhetoric of Reaction lists the standard three arguments used against social progress through history as: perversity (anything you do to help will only make things worse), jeopardy (any change will risk what we have now) and ..... futility (it doesn't matter what you do, nothing will change). Bell Curve very strongly following this latter rhetorical strategy. These arguments naturally re-occur when you're arguing against something that everyone knows is a good thing, just as FUD is a popular sales strategy when you're a comfortable monopoly. You don't have to claim to be good or even just better, you just need to undermine the alternatives and the status quo survives a bit longer.
