Problem is, GPA is incredibly subjective across different schools, hence the need for standardized testing. Do you rank someone that has a 3.5 at a boarding school where they were taking college level math classes at Princeton as less qualified than someone that has a 4.0 at a school where half the students aren't literate?
Agree. The place I went to HS had a 4.0 grading scale. There was no other high school in my town. Several towns over, their school district decided that AP classes should get weighted grades, putting me at a comparative disadvantage within the same curriculum.