Basically, schools in the south in the U.S. don't prepare kids for college one whit, and this is what happens.
I have to disagree with that. There are several public high schools in my area (in the south) that do prepare kids for college. I attended one of them. You can't generalize schools in the south since there are public schools that are good and some others that are improving. I'm pretty sure there are schools all over the U.S. that don't prepare kids for college. Also, it's not always the schools' fault students aren't prepared. There's a rampant case of laziness going around and the schools can only do so much.
My elementary school was targeted to test out new versions of standardized tests because the school had achieved high scores in previous years. It seemed like every other week we were taking one. I've heard several of my teachers during middle school and high school complain about standardized testing. It wastes so much time preparing for them. I remember whole weeks being blocked off to review before a standardized test.