Why is there a common assumption that additional prep is needed?

If a school has a history of 2’s on AP tests, then have your kids take that class online with a reputable online school. We had a teacher who started APUSH with a speech about how they would probably get 2’s. Our concern was not the scores, but the learning. Our kid loves history. She took it online, loved the class and byproduct was a 5. This was better than prepping because she actually learned something long term.