I'm worried about it because I live right in the middle of the most socialistic, anti-weapon crowd in all of America, without venturing into San Francisco itself, that is.
I'm not worried so much as being cautious. People in California don't mind their own business, especially here. Give it enough time, and someone WILL call me on that funny-looking clip visible in my right-front pocket.
Now your being paranoid. I've lived in (and carried a knife in) Los Angeles most of my life, currently live in Santa Monica, visit schools quite often, usually with some kind of knife clipped to my pocket.
IF you act like a suspicious paranoid gun nut whacko/knife nut, like you are making yourself out to be, you bet people are going to scrutinize you as such. The solution is simple: don't pull out your knife, and chill out.
This isn't really hard to do. Consider this: Cigarettes are also banned on campus. To follow the letter of the law, you can leave the pack of cigs in the car. Realistically, you can just not light up on campus, an nobody will know any better.