The point isn't that there's a desire to use a firearm, it's that there's a desire to have a CHANCE to defend one's self.
Maybe, but it doesn't sound like that is what's going on in this case.
He doesn't want an alarm or anything to deter those guys from approaching and entering his house, he wants something that will simply announce their presence. It almost seems like he is wants them to come in. Of course if he lives in a jurisdiction with castle laws, then he can pretty much do anything he wants in terms of defending himself once they are inside.
Personally, I think that most people would want to take reasonable measures to stop unwanted visitors from entering the house in the first place. I also think that most people intend on using their weapon as a last resort once all of the other security measures have been breeched.
Hell, he might as well just leave the front door open and invite them in!