I mean, not really? Uneducated parts of the population having disproportionate amounts of children wouldn't impact intelligence at all, like bro go back far enough and all of our ancestors were uneducated. Like it wasn't that long ago that 100% of parents and 100% of children thought if you pissed on a certain tree you'd get struck by lightning.

Idk. Honestly I get why they did it; I'm wracking my brain and the only reasonable explanation I can think of would be smartphones, which didn't exist when the movie was written. You don't know what you don't know, you know? Like I said it's still a good movie, like it's still funny and captures a fair bit of seeming trends, it just also sets itself up as a wet dream for people who think other people don't deserve the right to have children, which is a pretty core belief of the people we're trying to mock.