I guess those of you who don't like or are against "gun totting" Alfred haven't read very many Batman comics. If you dislike the notion of this then you'll probably hate "Batman: Earth One" and Geoff Johns take on Alfred.
Speaking for myself, whose read countless Batman titles in 25yrs, Alfred has used on occasion a gun in his 70years. Occasional gun use.
is not THIS
This is daily use, on the prowl as if he's Dum Dum Dugan or even Dominic Fortune.
Alfred with a shotgun or other firearm to AT THE RARE TIME defend the mansion, himself the cave is way, way different and you know this.