Code of conduct agreements by default are fine until it tramples on natural or expressly guaranteed rights.
A university could not expressly forbid carrying/reading of a Bible or forbid the use of verbal language among peacefully gathered people which are expressly guaranteed by the 1st Amendment---as everyone would rightly raise hell over that. But with rights to self protection guaranteed by the 2nd Amendment get trampled daily.
Only because hardly anyone challenges it to the ultimate end.
Jimmy takes his rifle or shotgun to college because he wants to hunt on weekends. His jackleg roommate does something and he gets found out for having a firearm. University expels or suspends him. Parents don't have money to fight it, NRA or GOA can't or won't support every case like this (because they're not noteworthy enough) and Jimmy is out, his 2A rights trampled, the university emboldened and anti-gun people yelping about how they succeeded in getting a dangerous person gone who could've massacred thousands with his semi-auto magnum revolver riflegun.
