Ignore stupid rules unless there is a metal detector.
Ignoring a university's "stupid rules" is a great way to get expelled. College can be expensive, and if you get expelled for violating university rules, you don't get a refund. And good luck getting accepted at another college when they find out you were expelled for a weapons violation.
Even if there are no metal detectors, it still might be possible to have ones knife discovered. Like for example- if it falls out of your pocket or bag and someone sees it. And if I recall correctly, campus security have the right to search students (empty your pockets, bags, purses, etc). Several times I've heard of campus security searching students when there was a weapons scare on campus. None of this may sound fair, but no one has a constitutional right to attend the college of their choice. If a student violates the rules, or refuses to let themselves be searched, the university has the right to expel them. Why take the chance just to carry a knife that you aren't going to use anyway.
Sometimes in life, to get what you want (like a college education) you have to compromise on your personal desires (like carrying a knife). And it's no different in the adult world of having a job. Many workplaces don't allow knives. And if you ignore the "stupid rules" at your job, you get fired. And good luck getting another job when perspective employers find out that you were fired for violating the company's weapons policy.
In California, it is illegal under state law to carry a knife on ANY college campus with a blade longer than 2.5 inches (California penal code 626.10). People attending college should do more than read their university's rules, they should also check their state laws.
Civil disobience to unjust laws is an American tradition.
So is sending people to jail. The US has the largest inmate population on earth. You can call your illegal actions "civil disobedience", but the cops, prosecutor, and judge, are going to call your illegal actions "crimes". Good luck violating a weapons law in this country and trying to win your freedom by calling it "an act of civil disobedience" in court.
Here in California it is also illegal to carry a locking folder, or any knife with a blade longer than 2.5 inches on a public school campus K-12 (CA pc 626.10). When I go to my kids school, I carry a small non-locking folder. If I need to defend myself or anyone else while I'm there, I have my hands and feet. If I were close enough to a threat to effectively use a knife for self-defense, I would be close enough to use my hands and feet. And there are usually lots of metal folding chairs around which can serve as effective improvised defensive weapons if the need might arise.