None of this surprises me. It isn't cool to be smart. It's more fun to tease smart children than encourage them. Read the comments to the link. Smart people are the Intelligentsia. They are elitist. They "rub it in." Sports matters more than grades (ever seen a parent plant a My Kid Made the Honor Roll sign in their front lawn? Better they make the cheer squad or play football). Being smart isn't something you share. You keep it quiet so the dumb people won't feel bad. God forbid we have Valedictorians or Salutatorians. The kids who didn't make it might be sad.
Americans beat their chest with pride and are full of WE ARE NUMBER ONE but tell them their kids scores are the laughing stock of the world's schools and we can't hold a candle to what the kids learn in Europe and Asia (nor find it on a map) and we are quicker as a nation to say "who cares about them" than "how do we fix this?"