It's because America's school system is corrupt. Of course, they would shove a bunch of students in a classroom who have different aspects in learning. They value students who are fast learners of course and despise flunking students just cause they can't cohabitate in what they are learning. The whole purpose of school is for us to get used to a factory/office environment. Doing things that will not satisfy us in our near futures and be being pressured under a schedule. Honestly, High school is mainly trash for this reason. Honestly, in general, we are practically learning the same stuff we learned in first grade it's just that it advances more each grade you go up to. What a waste of 12 years of youth.