The only reason some things are upheld as legal or illegal is because of the power of the people who say that they are legal or illegal. That's all.
Almost anything is legal for any man or woman. It is only slave makers who say that things are illegal for other people.
If the weapon is in the house, it will sooner or later shoot. Different situations happen, especially when the storage is not properly fatal house.
Accidents occur because of this constantly. I'm not talking about mental disabilities of family members.
I and many of the people I know have had guns in the house forever. In my area it is probably an uncommon house which doesn't have guns kicking around. I've not ever had or even heard of an accidental shooting.
The only person I know who accidentally shot himself or anyone else was a friend of mine in the military. As a teen he had a black power pistol which he was practicing quick-draw with and got himself in the thigh. On the other hand, I know of many many accidents involving snowboarding, rock climbing, horse and ATV riding, etc. One of the kids in my mother's class in the 1950's was killed in a hunting accident (similar to the non-fatal accident involving Dick Cheney.)
Basically you are describing a situation which does happen although it is rare and not an example of the low-hanging fruit if saving life and limb is your real purpose. I can promise you that if we in my rather blow par economic area with very minimal law enforcement personnel did not have a high percentage of homeowners being armed, death and injury rates would go way way up due to an increase in confrontational crime. Basically in only happens now when a tweaker is caught doing property crime against a home or shop which they think is unoccupied. And typically all it takes is the threat of being shot to de-escalate the situation so no injuries are realized. In fact these instances often go unreported.
I will grant that suicides are not uncommon in my area and they do commonly involve firearms, but I would suggest that in many of these cases another method would be found by someone serious enough to pull the trigger.