Are high schoolers lazy or stupid?

Take a look at this article entitled “They’re Not Stupid—They’re Lazy: The real reason American high-schoolers have such dismal test scores.” It continues to highlight the problems of incentive-driven testing.
“When states begin imposing penalties for failure, it makes a difference—sometimes a big one. Look at Texas: In 2004, results counted toward graduation for the first time, and pass rates on both the math and English portions of the test leapt almost 20 points.” Of course, college admissions test scores have been improving too. But neither SATs nor TASP nor THEA say anything in my opinion about intelligence. They they are, in my opinion, solely indicators of motivation to learn for the test. The author suggests that kids are lazy. Anyone in school would tell you that kids are rational–they’re lazy about things that don’t matter to them. But isn’t that, in some sense, smart?