Well in scenario #2, if I was a burglar, I would think "well, everyone carries a gun, so as soon as I break in I will shoot first if I see any movement" whereas in scenario #1 I would think "well no one carries a gun in their homes, so I don't need one, a knife to intimidate them will do and I don't risk of getting my *** shot too"
Guess which scenario has fewer dead people at the end of the day? Burglars will burgle, junkies and addicts will commit crime, that won't change because you and I are carrying weapons. Idiots will continue breeding no matter what.
Oh, by the way, just because you are a burglar it doesn't mean you have easy access to weapons, that is a perpetuated myth that every outlaw can get a gun easily.
At any rate, I - as a citizen - am not willing to kill someone or increase the chances of getting killed by someone, which is very possible to happen if burglars think you have a gun (i.e. come in armed and ready to shoot).
Do you think robberies and burglaries have gone down in places where guns are legally owned and carried? It would be interesting to check that.