Note that the USA scored better than most of the rest of the world in this and several other basic science questions. The actual result is "humans aren't well-educated"; it's being cynically spun as "Americans are stupid."
Nor should it, but you need to understand the scope of the problem before you can address it. The original headline invites millions of people to say "haha, look at those stupid Americans, they sure are stupid" and continue ignoring the problems in their own nations. We can do better than that kind of bullshit tribalism.
