I bet if you looked at it, the mean ESTJs GPA would pwn the mean INTJ's GPA. INTJs are often too smart for a lot of the routine work in HS and ignore great portions it, just like their smarter INTP cousin do!!
although, if you're talkign standardized tests..... yeah, INTJs are gods there!
School is geared towards the ESTJ at the basic level. Regular dificulty classes have groupwork, and just require the students to digest the textbook. The teachers also require organization, which the ESTJ's often excell at. Finally, the mathematics requires structure and logic, which ESTJ's I know have a lot of, meaning that the basic level education is for ESTJ's. The honors and AP levels were pretty much invented for INTP's and INTJ's.