I think you need to be careful about painting with too broad a brush. Some community colleges are very good; others not so much, in terms of rigor and class offerings. And many high schools, both public and private, offer very rigorous classes, which would give introductory courses at many universities a run for their money.
Everybody needs to try to assess their student’s unique aptitude, preparation, and drive. Better to err on the safe side for most, especially those with premed aspirations (where both a high GPA and class rigor are key). For many, however, it just makes no sense to repeat a class solely for an easy A. Believe it or not, four years (eight semesters) is not that much time to explore a range of subjects, especially if your major has a very demanding and/or proscribed “flowchart.” Why waste a class?
IMO, I think past generosity with regard to the Presidential Scholarship masked a HUGE range of aptitudes among “top” students. There’s a very big difference between a student who graduated with a 3.8 weighted GPA and took the ACT three times (after prepping all summer) to finally achieve a 32 and another who has a 4.0+ unweighted and got a 35 the first time she took it. Also, there’s a wide chasm in terms of preparation (regardless of innate aptitude) between the student who attended a small public high school with a few (or no) APs and someone who attended a magnet or elite prep school where Calc 3 and Differential Equations were offered.
Some kids will enter into engineering or other very challenging majors and hit the ground running because of previous preparation (both in terms of subject matter and experience managing heavy homework loads, etc.). Other very bright students will stumble because they’ve never had to deal with the demands of a college-level weeder class and “just don’t know what they don’t know.”
Again, I think it’s best not to generalize. Too many variables - which is why you need to know YOUR student.