Okay, that's fine...
If all else fails then yes, I'm sorry, but yes, if somebody breaks into a house and threatens my family I will threaten them with force. The lives of 4 people who are innocent are greater than that of one who willingly put themselves into a criminal position. Do I wish that that wasn't necessary, sure, but that's not the reality of human nature. The threat of force has always been a factor in survival. Even in nature.
Poison caterpillars rarely get eaten, the birds learn to avoid them.
Gun ownership is widespread in the US, and lots of people have them in perfectly safe regions. So do they not create a source of danger where there was none? Accidents do happen.
In my country, gun deaths went down considerably after the police started taking them out of circulation. As one police officer put it, bar fights became a lot less deadly in the suburbs.
That's a gross oversimplification of a complex issue. Very few people obtain a handgun legally for the purpose of Murdering somebody. (Less than 1% of legally obtained firearms are used in a crime) The primary reason to own one is for personal protection which implies the direct preservation of life. Ignoring that fact is intellectually dishonest.