Oh so your idea is we shouldn't criticize scientific racists because they're right? No, we criticize them because they're wrong, the whole thing is made up pseudoscience as window-dressing for bigotry.
It is extremely deniable that intelligence distributions are "not the same across races" (whatever it is we might mean by "races"), and by citing Alexander as your support for that claim, your argument has become circular.
Citing another blog post that defends it, while conveniently ignoring every other point being made by researchers https://en.m.wikipedia.org/wiki/IQ_and_the_Wealth_of_Nations