Edit: To clarify, I've used knives professionally (diving instructor) and recreationally (kite surfer), but I fail to see the non-weapon use for a knife that is small (and therefore concealable) and also opens quickly. Not to mention the window-smashing attachment. 
That can be handy when trying to rescue someone, or so my volunteer firefighter friends tell me. Claiming that such a feature has no legitimate purpose is like claiming that a crowbar has no legitimate purpose.
"I fail to see the non-weapon use for a knife that is small (and therefore concealable) and also opens quickly"
Small knives are easy to carry around, that should be obvious. As for opening quickly, that is just a convenience -- why should convenience be frowned upon? Would you be less concerned if these were fixed blade knives?
Sure, knives and crowbars are weapons when you apply them to human beings. People have been murdered with screwdrivers (is a small screwdriver a bad thing?). On the other hand, the NATO e-tool, designed for use by soldiers at war, is often used for gardening because it is convenient -- it can be used as an ax, it can be used as a shovel, it folds up for easy storage, etc.
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.
I keep glassbreakers and seatbelt cutters in my car with easy access, and also have tools which can break glass. I've been to two (civilian) vehicle accidents where that was incredibly useful -- being able to break the glass to access a person in an upside-down or sideways car from the outside. I had a glassbreaker for one, and the other I had to use a crowbar, which kind of sucked. I don't really see a "weapon" use of a glass breaker, particularly if you already have a knife or firearm to hand.
I also used a kershaw AO knife all the time to cut things while holding something else -- for instance, cutting open dressings while holding pressure, since someone had taken my shears. Or opening a cardboard box while holding it.
The very existence of these knives is clearly to circumvent existing laws regarding switchblades.
This is entirely separate from the big-guys vs little-guys argument being made against Google.
Those laws should be circumvented; they are as stupid as laws prohibiting Bowie knives.
They're just more convenient.