The annoyance with 10-20% means that in order to be an "A" student you have to do all the homework instead of just ace the exams which is obnoxious if you actually know the material. Edge case, I know, but that last 20% is a ton of extra work.
I wish it was only 10-20%. I'm a non-trad student at a small state school and IMO they try to inflate grades via homework. This semester I aced my exams, but only had time/energy to complete ~60% of my homework. Since it was 30% (on average) of my final grade I ended up with a 3.0 for the semester.
It is an edge case… I mean, if people are required to take classes where they already know all the material, somehow a failure has occurred earlier in the process (unfortunately it is a very common failure mode to not be allowed to try and test out of a class).
Realistically I think the more common case is to think you know the material, skip studying, and then faceplant on the test. Homework should help self-correct.
But yeah, I could it being annoying if you really do already know the material.
The course could offer nonlinear grading where you get the maximum of [exam grade, 0.8 exam + 0.2 hw]
A lot of my university professors would use this kind of strategy where your final grading structure depends on various grades you got throughout the semester, so all students could get good grades whether they ace the exam or they are terrible at exams but excel at project based learning/labs.
You're there to pass and get your diploma. If you want to excel, there are other real venues for that ambition.