one thing is the odds are 3 to one against the knife striking your target point first. My variant always strikes point on. other problem is that after you throw it, you have no weapon. With my design, after you throw it, your knife is still in your hand.
since the subject is raised --- I have seen throwing knives for sale and most times they are sold in sets of 3 . They are either handle heavy , blade heavy or balanced and there are different techniques to throwing each type . I've never thrown knives but think that its a cool skill same as throwing an axe or tomahawk or using a slingshot . Checkout a utube vid on - The BEAN SHOOTER - for some slingshot entertainment .