Simply put, the presence of a gun in the home significantly INCREASES the likelihoods of both robbery, and domestic violence. There is no available evidence to suggest that the presence of a gun mitigates of any of these things. Adamant gun rights activists will insist that’s because there’s no data, because obviously the the things didn’t happen, therefore there is no data. But that’s nonsense; I could say that the absence of my farts have saved just as many lives, and you couldn’t un-prove the negative.
There are also far more demonstrable positive values to stair ownership and ladder ownership. Look at the data comparing frequency of use to injuries.
It is demonstrably false to say that malicious use of firearms is a criminal issue. Most gun deaths are suicides. Most other shootings involve people who know each other. Random gun crime is truly random and mostly statistically irrelevant.