Interestingly, we had the opposite experience. My D’s college took almost all of her DE credits - CC DE courses actually have a higher acceptance rate than U. Of Pittsburgh DE classes from our HS. A C- is all that’s needed. I don’t think anyone didn’t get a C- in any of her DE classes, probably 95% A/B.
APs required a 4 or 5, pretty standard for all the schools we looked at, and less than a third of AP Stats exams received a 4 or 5 grade last year.