I think it's pretty simple. Anytime there is discrimination (however so small) it makes you feel like you are looked down upon. When you are looked down upon you don't feel welcome. (That being said, there are various ways to deal with that feeling, and throwing a tantrum isn't the best way.)
I really don't know what is the best course, but what If there was a way to change the HC so there is no gender discriminating verbiage, yet uphold our standards to not condone promiscuity of any gender. Then we can say that they are welcome to attend BYU and live celibate while attending? If they want to graduate and go have a life partner or get married after BYU, then great. Best wishes on a happy life. Isn't that how we deal with any non-member and their way of life who attends?