In addition, admissions based on GPA means that students are motivated to choose easy classes and lenient teachers whenever they have choice. IMO, system should not punish students for choosing out hard classes - if anything it should reward that.
I don't remember my high school report card having a difficulty rating on the class. I would be very interested in data on the number of high schools that do this weighting.
When I was in high school in the Dallas area, AP classes were all weighted one-step-up-the-scale. A's were 5, B's were 4, etc.
I forget the max GPA in our class, it was somewhere between 4 and 5, but I don't think it was the theoretical max you could get if you took as many AP classes as possible and got A's in all of them.
Colleges weren't stupid about it, either, though. My brother had a lower GPA since he went to a smaller school with very few AP classes available, but did better relative to that curriculum than I did relevant to mine's, and he got more scholarship offers and quicker admission offers at the schools we both applied to. Even though my SAT was 10 points higher.
We had pretty strict biology teacher and pretty lenient physics teacher - both classes equivalent of AP. So I would pick physics if GPA mattered to me a lot.
