They will likely be traumatized either way

It's perfectly true. I see people excited by the idea of shooting a burglar. But if they have to do that, they'll understand that the reality is not what they imagined. It's traumatic to be burgled, but even more to be burgled and killing someone, at least for decent people. And I think most people in this thread are decent, their imagination is just corrupted by a fucked up culture. I'm just trying here to state facts to counter this culture.

I don't see any other reason for people to prefer a firearm, which is dangerous for the owner and the owner's family and if used “successfull”y will leave everyone ever more traumatized over actual security systems and deescalation technics.

In Germany it's literally illegal to sleep with a gun under your pillow as you are violating gun storage laws. This already makes your claim to self defense very murky. Because why are you breaking the law in the first place?

It could be argued you intended in advance to shoot whoever entered your home which would then constitute murder.

§ 34 StGB Justifiable Emergency.

Anyone who, in the face of an imminent and unavoidable danger to life, physical integrity, liberty, honor, property, or another legally protected interest, commits an act to avert the danger from themselves or another person does not act unlawfully if, upon weighing the conflicting interests—namely, the legally protected interests involved and the degree of danger threatening them—the protected interest substantially outweighs the interest that is impaired. This applies, however, only to the extent that the act is a reasonable means of averting the danger.

The right to personal property never substantially outweighs the interest of another person to stay alive. You must be (about to be) attacked to be able to resort to a gun.

No, per your own link: “The act of self-defense must also be reasonable”, that is, proportionate.