I agree with kraigwy on the ease and speed in which someone can get into a residence. Better to have a firearm on you.
For another, hearing the attack start on others is only useful if the others are attacked before you are. If you are the first, or one of the first, then your argument has no meaning.
When my local college put "active shooter" procedures in place, one of the procedures was to lock the door. The first question I asked was, "What if he's in here?"