>I fail to see the non-weapon use for a knife that is small (and therefore concealable) and also opens quickly
I am an Eagle scout. Being able to quickly pull a knife out and open it one handed, due to it being assisted opening and small enough to clip into my pocket, has been beneficial more time than I can count.
I have had a knife in my pocket nearly every day since high school. I have used it thousands of times in that time period. I never once used it as a weapon.