As has been said, a rock or a knife is a better weapon. In some cases, a knife, cudgel, rock, blackjack, ect., is more useful than any handgun, and in many self defense situations still a capable weapon in any case. The firearm's primary advantage is distance, more than any other factor. A rock, a club, a hammer, a knife can be whipped out and used quickly and violently, this little thing is too slow for a self defense short range fight, and it only offers you one chance with an inferior caliber to perhaps stop an attacker.

I like full size steel frame guns for many reasons, and one advantage is they are heavy and strong enough for close range combat. A 1911, a Hi Power, steel revolver, can all be used as powerful crushing weapons, something a light polymer does not do very well. Unloaded, my 3 pound M 27 can still bludgeon an attacker, something this card is utterly worthless at.

Think of it this way: let's have a gladiator style fight to the death between someone carrying an unloaded N frame 6 inch barrel revolver in a side holster against someone with a LifeCard 22 folded up card style in their pocket loaded. Depending on the distance, there is a good chance the guy with the loaded gun will be tied up, or bludgeoned, by the time he can employ his firearm, and if he pulls the shot anywhere but a major vital organ, he'll be fighting the guy hand to hand anyway. Its a silly hypothetical, perhaps, but maybe telling.