I don't want my kids to have to deal with roommates doing immoral things in the bedroom next to theirs. I don't want my kids to have to compete for admission and scholarships with people who don't intend to live the HC. If my kid doesn't want to live the HC, then I don't want them to go to BYU.
Unfortunately, enforcement is fairly complex.
My limited, second hand experience with the HC is that if you are called into the HCO and deny the accusation, you will be just fine. If you admit you did something but provide a reasonable rationale, then you will get punished.