[tremon]

That's not a eugenics argument, that's merely an evolutionary argument (identifying a change in selection pressure). The eugenics argument would first have to make the case that the people are stupid/intelligent because of their genetic lineage rather than their upbringing.

[lynndotpy]

To repeat, in narrative, they attempt genetic engineering to fix the declining intelligence.

On top of that, it is explicitly a dysgenics narrative, which comes with an implicit eugenics argument unless it's explicitly addressed.

I'm not trying to argue you can't like the movie (it is fiction, after all), but the eugenics argument is right there in the text.