To have an athletic program. Sure, you lose the easy transfer to D1 that came with JC status, but by getting rid of sports altogether, I wonder if alumni connection to BYU idaho will be significantly reduced in the future.
I have asked several BYU idaho grads when was the last time they returned to campus after graduating, and with the exception of those who have family in the area, none have returned. To me that sounds like an alumni relationship more akin to University of Phoenix than BYU. Without alumni carrying a strong bond to their Alma mater you risk low donations, fewer legacy students, and other weaknesses long-term. Seems like they could also help appeal to current applicants by fielding a basketball team. Could be a great basketball environment up there