Knives are horrible, horrible weapons.
These are clearly NOT intended to be used as weapons, as they are normal, everyday lock-back knives. Knives intended to be weapons, such as those modeled after the Krambit design, are fairly rare in public, especially among people who use knives (their shape and features make them much less useful). Your outrage is misplaced - we are not having a weapon talk.
Google not allowing ads for something that is legal is bullshit. Them not allowing ads for some people, but allowing them for others, over the same product, is evil.