nailed it. I see this odd "eugenics" framing all the time, and all I can think is 'ooh la la, somebody's gonna get laid in college." you can argue the academia until you are blue in the face, but the real-world statistics show that less educated people have more children and that education quality in the US has been declining. It's not a foregone conclusion that one causes the other, but there's a cogent argument to be made that it's about the culture of poorer people vs the culture of richer people - and they even spell out that angle in the movie. They show how reticent the rich couple is to have a child, and how eager the poor couple is to do the same. It's about what their cultures value about children and legacy. It's not "dumb people make dumb kids", it's "dumb people won't educate their kids past their own knowledge who, in turn, won't educate their kids past their own knowledge." The movie even goes on to resolve with the "dumb" descendants learning (from the protagonist) when they have anyone willing to make that a point of the culture. So I can't read a clean "eugenics" take from the film; I only find that take in misreadings of the intro, personally.
I agree the eugenics thing is tangential. It's just there as an easy way to advance the plot to the point where the real story can start without too much work.
You could drop the eugenics thing, replace it with cultural indoctrination of some sort, re-frame it to instead of shitting on white trash culture, shit all over the college educated white collar white people culture and have the same movie down to the "culture has so thoroughly run amuck that even the black president is white in a bad way" trope, the trash piling up because we don't know what to do with it and the heroes being a hooker and a lazy army private. Maybe you'd have to replace the demo derby with a committee hearing full of say nothing corporate speak and some other minor details.
