It's pretty obvious that human biodiversity and race realism are just politically correct euphemisms for scientific racism. The only reason that we use those terms is to put people at ease because modern sensibilities have been so skewed towards automatically and violently rejecting White bigotry. But the idea that scientific racism has been thoroughly debunked is a talking point that anti-racist liberals like to spout in order to discredit our ideas. And just because certain aspects of 19th century and early 20th century scientific racism were nonsense, that doesn't mean that everything that they espoused was nonsense or that more recent scientific racism is just a rehash of discredited ideas.

Reality also isn't a popularity contest. I could be the only person in the entire world that believes that not all racial groups are equally intelligent and civilized, but that wouldn't mean that I'm wrong. Yes, we know that the scientific and academic community completely despises us, but that isn't because our ideas are BS. Our views simply aren't politically correct.
Eugenics is a perfect example of a completely valid scientific idea falling out of fashion simply because it offends modern liberal sensibilities. Not only is it possible to improve the human gene pool through genetic screening, embryo selection, cloning, genetic engineering, selective breeding, polygamy, artificial insemination, et cetera, but it's absolutely vital to the long-term health of our species and our environment.

It's widely known in environmentalist circles that human overpopulation is the root cause of most environmental issues. Everything from climate change to overfishing is mostly caused by too many people living on this planet. So, if the human population needs to be dramatically reduced in order to fix this problem (which most scientists and environmentalists are hesitant to publicly acknowledge because they don't want to be accused of being evil Nazis), then eugenics is obviously the most logical solution to this problem, because if you have to dramatically reduce the human population then obviously it just makes sense to select for the best and the brightest.

Who wouldn't want to live in an environmentally sustainable society that had a guaranteed income, an army of AI robots (but not so smart that they pose a threat to us) to take care of the dirty work, and a beautiful and healthy citizenry comprised of Mensa members? We'll soon have the scientific know-how to make that neo-Nazi utopia a reality, but what we lack is the political will to implement it (thanks to the progressive Left). The Alt-Right exists to solve this problem.

Dysgenics is also a massive problem that's being completely ignored because the solutions lead you down a path towards the Fourth Reich.
Eugenics has to be one of the most important and powerful ideas in all of human history, but it's being suppressed simply because it reeks of Nazism. So, while the progressive Left just loves to claim that the conservative religious Right is getting in the way of scientific and human progress, when it comes to eugenics it's the liberal Left that's preventing our species from making the next major leap forward.

You can tell that the scientific community is completely terrified of new developments in genetic research bolstering our racist weltanschauung. Once we get a better idea of which genes are responsible for human behavior, we'll finally be able to solidly prove that some racial groups are inherently superior to other racial groups. You can also tell that the scientific community is extremely nervous about discovering that the genes that are responsible for intelligence won't be evenly distributed throughout the various "population groups" (the politically correct term for race). Acknowledging that racial and class differences have a genetic basis will completely undermine the central pillar of modern progressive ideology.
Scientists like James Watson and Hans Eysenck weren't quacks. They were treated like heretics for daring to dissent from modern progressive orthodoxy.

If you want to learn more about modern scientific racism, then you should check out people like Stephen Hsu [1][2][3]. He's allowed to get away with espousing racist, Nazi-ish ideas because he isn't White, and because he's very careful to moderate his views by paying lip service to progressive egalitarian ideology.