This is a great example of Goodhart's Law, though. If nobody studied for the SAT, it might (arguably) work fine as a measurement of collegiate potential. But because it became the metric for collegiate success, and because the "practice effect" means that practicing makes you do better on the test, many people study hard for it and greatly increase their likely score. The folks who don't study as much or as effectively for it for whatever reason will not do as well, as so you're left with a measurement of whether people studied for the SAT and not whether the test taker would be likely to succeed at college. So a good metric becomes a bad metric because it's chosen as the metric.