Having a gun and carrying a gun doesn't mean you will survive a home invasion or attack. Think of the LE people who are intimately familiar with their weapons and have died with it still in the holster.
What the gun does is give you more of a chance. You will not necessarily win.
For those people who see no need to have a gun or learn how to use one, they may scoot through life just fine an not face a shoot or die situation. In fact, the fast majority of people never shoot at a human.
Also, so many people who want nothing to do with guns will someday wish they had one when it's them or the intruder. Not many persons who see no need for a gun in the house, will lose that mindset within seconds if the need arises. The most timid person you know would shoot to kill before he/she permitted serious harm or death to a loved one. In fact, I think any rational person who believes in staying away from guns, would use one if he had it if a real need came to visit.
I am presently on a two week vacation. I didn't want the hassle and risk of checking a gun on the flights, what will all the plane changes and possible airline thieves. So here I am, as nervous as a cat. No gun for the first time ever, and that's a long time because I'm old. Never again. I know now I'd rather take the chance of it getting lost or stolen and not to have one for two entire weeks.