I am in full agreement with the idea that one's home is his or hers to defend if need be.
This isn't some tough-guy bullshit. It's about making a dedicated attempt to preserve your life and those of your family.
OF COURSE you'd weigh your options, for as little time as humanly possible, but if someone or a group of people enters your home unwelcome and with obvious bad intentions, and your family or friends are there, are you going to think it out ... or assume the worst case scenario (the wise move) and do what has to be done?
As well, OF COURSE it might go bad for the home dweller, but as has been said, nothing in life is certain.
If I visit someone else's home, and I am welcome in, I act accordingly and with respect towards it being THEIR HOME.
Good people cannot roll over or give any quarter to those who would intentionally do harm.
P.S. For those who care, YES, I have been pepper sprayed. It was a component of my training at one time. Horrible, horrible scene. Shot directly into your eyes, it's a living hell. Still, if I had the choice, I'd be spraying bullets all over the damn place like a coked-up Rambo.