As a side effect from increasing population people are more inclined to do physical violence. Because it´s not socially acceptable they refrain from doing so. Hence they assume that a person who carries a blade is more likely to act violently . It´s not easy to change the perception of the society under those conditions.
I usually carry a Buck Crosslock in a pouch on my belt. I don´t care too much about other people´s reactions to that. I don´t go to events where the audience can´t be trusted to carry a pocket knife and let people know about that. Data supports that attitude. You can frequently read about fights at events where people are not allowed to bring a blade but you don´t get news from fights at events where virtually everyone carries a knife. When you take in account that there is a bias against knives that´s even more revealing.