To put my previous post more simply: We just never relied on the schools to educate our kids. We tried to turn the lack of rigor into a plus by encouraging EC’s in and out of school. The lack of homework meant more time for those. Reading at home, and using online courses and other resources, rounded things out. I will say that our school asked kids to write papers, but there was no instruction on how to write them!
I do not think the message should be that students educated in mediocre schools should avoid rigorous colleges. I have read that the well-prepared students are often jaded, and that professors prefer the kids who didn’t go to prep schools etc. The students who are new to real learning at college can be the most excited, once their skills catch up in the first year or so.