Education is different than proselytism and advocacy, wouldn't you agree?   There could be a scholarly course on Islam on a Catholic University, but that would be different than having a group on campus which actively promoted and proselytized for Islam.    A muslim should be able to attend a Catholic University without being accosted for their faith, but at the same time, should receive a solid understanding of what the Church truly teaches in her Doctrines on Faith and Morals.  What you call 'learning', maybe you really mean counter indoctrination.   If I chose to attend a school run by Seventh Day Adventists, I would have a no expectation that they would allow a group ON CAMPUS 'promoting' Catholicism, I would not expect a Jewish University to serve anything but Kosher Food.  Both schools could offer courses respectively in Catholic Teaching or 'non Kosher Food' without undermining their particular mission.   Wouldn't you agree?