After a second they'll reply that ipods and lipstick aren't weapons. Everyone knows that "anything can be used as a weapon", but tactical knives are weapons. That's their purpose. If I saw someone whipping out a Military, Rajah II or some other large folder I'd be wary of the person. Why should I assume that a stranger knows proper knife handling skills or assume that he is a good person?
And that's entirely the point. It has nothing to do with "liberal indoctrination", voting democrat or republican, or the "superiority" idea that some seem to think is reality. Most people don't trust strangers with large, pointy weapons. If you have no idea what someone's background or intentions are why would you trust him? People "freak out" because 1) they aren't expecting others to carry large, tactical knives and 2) if they don't know you why should they feel secure around you? This has nothing to do with the 2nd amendment, carrying rights, or anything. Knives are not commonplace and the tactical ones that people carry look threatening. With all the talk of "knives for self defense" on here it's hilarious to see people choose "the best knife for self defense" and then consequently flip out when people recognize that they are carrying a weapon. There must be some sort of mental disconnect there to not realize that, yes, tactical knives are weapons and people are rightly recognizing them as such.
So, try carrying a traditional slipjoint around. Try a peanut, a swayback jack, a medium stockman or some other useful pattern. Get one with some nice chestnut bone or stag scales. People probably won't freak out and if they do you can use it as an opportunity to extend a bit of knowledge and courtesy as an ambassador of the knife community.