BYU-I's purpose is different than BYU's. They provide a quality college education for anyone who wants it; even linked to the Pathway program, giving people a path who haven't finished high school. I think it is a great alternative for those who cannot get into BYU.
I do agree that people should be proud of their degree and reference their school, BYU-I, with confidence. That is the only way BYU-I's reputation will improve.
BYU's 52% is more selective than many universities, but nowhere near the few elite schools, like Harvard, Stanford, and MIT. But not many schools are at Harvard's level and it would be unrealistic to compare most schools to them. A key measure of BYU's desirability is that 81% of those who are accepted enroll. For example, Clemson has a 29% enrollment rate. That puts BYU's enrollment rate right up there with the elite schools. People who apply really want to go to BYU.
See this post for other universities' rates and the source:
https://www.cougarboard.com/board/message.html?id=21169492