if they think there going to get in. If they don't have the grades, aren't LDS, don't want to live by the honor code, etc... they apply elsewhere. That makes the pool of students who actually want to go to BYU much smaller than those who want to got to Harvard. So acceptance rate isn't really a good measure of how good a school is. You have to look at the quality of the students they are accepting and the quality they are accepting is the same as those going to those Ivy leauge schools.