It’s not the selectivity of a school, it’s more the size of the school and their admissions team. Smaller schools, regardless of caliber, can take the time to look over every application and then re-weight the grades on the transcript. The big publics (regardless of prestige) are the ones that just can’t time to look at every application. Generally the admissions people are very familiar with the area schools and their school profiles will explain their weighting system.