Any weapon is better than no weapon at all.

While swords aren't exactly my home defense weapon of choice, they can be very effective in a pinch. I'd rather have a gun, but there's no denying that the distances in homes are rather short, allowing you, or the home invaders to get close - at which point a sword, or even a large knife (especially one designed with fighting in mind) can put a serious hurt on anyone, no matter age or size.