First, Contrary to popular belief... the football program does not run BYU.

Second, When a head coach sits down with a recruit's parents for the very first time, one of the first things he talks about is his schools GSR (Graduation Success Rate). No parent wants their kid going to a school with a poor GSR.

Third, What most people don't know is that the NCAA holds schools accountable for academics through something called an APR (Academic Progress Rate).

Quoting from the rules...
"The Academic Progress Rate (APR) holds institutions accountable for the academic progress of their student-athletes through a team-based metric that accounts for the eligibility and retention of each student-athlete for each academic term.
[...]
The APR system includes rewards for superior academic performance and penalties for teams that do not achieve certain academic benchmarks. Data are collected annually, and results are announced in the spring."

Coaches get fired over poor APR. Parents don't send their kids to schools with a low GSR.

Schools will not admit players they don't think will graduate... IT IS A FACT. The kid could be the best player in the world, but if he's dumb as rocks he'll be gone before winter semester. IT HAPPENS ALL THE TIME.

There are no easy classes at BYU. The admissions board will not allow a player into BYU who they don't think will graduate. The AD doesn't want players who will hurt their APR and GSR. It doesn't matter how good they are.

BYU (right now.. today..) is an academically challenging school. The BYU of the 80's,90's and even 00's is gone.