I am curious if you have ever had anything stolen from your home, particularly something irreplaceable such as a family heirloom.
I've had things stolen - both from my home and from my car - but not anything I would consider a family "heirloom". I don't own anything I would consider a family "heirloom". Actually I don't think my parents do either. The only material possession I have that I actually value significantly is my intellectual property (I'm a writer). That's irreplaceable and means more to me than my entire life. But my solution in protecting it is not to have a gun, but to ensure it's well protected - all of the data is backed up every 6 months and kept in four different places, one of which is on my person at all times.
I guess the ultimate thing for me is, even if you do value some of your possessions that much (and I don't see anything actually wrong with valuing possessions that much, I note it as a difference, not a "flaw") having a gun and being willing to protect those possessions doesn't actually ensure they are safe. There's still a good chance that someone intending to damage or steal your property would still be successful, regardless of how well armed you are. Consider this. What percentage of time do you actually spend located inside your property, where you would be capable of preventing a break in?
(I also know from personal experience that it's quite possible to be at home in your house and still have someone break in and steal from you without you knowing).
Now, the possession of an easily accessible loaded firearm is assumably for one of two reasons - to protect life, or to protect property.
In order to protect life, you need to have the gun on you at all times. Having it under your bed is no good if you're in the lounge, or out driving in your car. Are you allowed to carry your firearm at work?
If we consider a likely life-protecting incident, how effective is a firearm as far as protection goes? Soldiers in combat carry loaded firearms, drawn and ready to use, often held at the aim position, safety off, ready to go. They are repeatedly trained to respond rapidly and effectively to any threat. Soldiers while on the battlefield anticipate and expect threats to their life at every moment. And yet soldiers are still killed in ambushes. All the time.
Why? Because if an threat to life comes suddenly and unexpectedly there's little you can do about it. Carrying a firearm in a holster is totally ineffective. And then consider the average citizen - they do not maintain any of the additional attitudes that improve a soldier's chances of surviving an ambush. Civilians do not have the same level of training. They are not anticipating a threat to life at every moment. They do not have weapons drawn, loaded, safety off. Citizens, also, are typically alone.
Thus in an ambush type threat to life situation carrying a firearm is not effective as protection.
What of the other type - a non ambush situation - some sort of confrontation escalates to killing.
Humans are biologically opposed to killing other humans. This is a fundamental factor of being a social animal. Social animals interact with each other through the behaviour of posturing and submitting, not through the fight-or-flight mechanism that results in intentional killing.
In a confrontation scenario, the liklihood is very high that the other person has no desire to kill you at all, but is merely posturing in order to dominate you. Threats of violence and even death are all part of that posturing. Once the posturing person achieves submission it becomes psychologically
harder for them to then intentionally kill you. Therefore your best chance of survival is to submit.
However carrying a weapon is itself a form of posturing, and mentally by carrying a firearm a psychological refusal to submit is established. So both parties then attempt to dominate the other through their posturing. This leads to escalation. Escalation is the most typical way in which a non violent situation becomes violent. It becomes violent because both sides attempt to dominate the other and neither side is willing to submit.
In this sort of situation carrying a firearm actually makes it more likely that the situation will escalate to the point of someone being killed.
So therefore a firearm is an ineffective choice for protection of life.
On to property. Property can only be protected by a firearm if both the firearm and the person using the firearm are present at the time that the property is threatened, and the person is
aware of the threat. In the instance of theft from a house or dwelling, I am speculating here, but I suspect the overwhelming majority of break ins occurs when the property is not occupied. As I myself have learned, in a large house it's also quite possible that your property can be threatened while you are occupying it, but you can still be unaware of it.
A firearm is therefore an ineffective choice for protection of property.
Balanced against this is the very real and undeniable evidence that the presence of an accessible loaded firearm in a house poses a serious risk to the the occupants of that house either through accidental firing or escalation of a domestic dispute.
So. We have a significant risk associated with possessing the firearm.
The firearm offers benefit against other risks, however those risks are very low, and the benefit the firearm offers against them is very poor.