It's fine if you have enough foreknowledge to prepare and to get your gun. But mostly you wont be granted such foreknowledge. Nobody sends you an email a week beforehand to inform you of their plans. They just turn up, shoot you, and 9/10 you wont have your gun there to do anything about it.
What? The criminals in your area don't have the common courtesy to call before coming? How rude! Outrageous!
Seriously, I see from your comment that I could at least
increase the possibility of having a gun on hand if a bad guy shows up, if I actually had one. There would be that 1 time out of ten, I'd actually have it.
My point is that I don't think I'm in a statistically likely scenario for needing a gun -- considering that most gun violence at least as far as I know, is either from suicide or gun related crime, among drug dealers/gangs. I tend to stay away from high crime areas, but some people do need to travel through those areas frequently.
But, anything can happen, and it can happen anywhere. I think if one is talking about statistics, one would have to consider that in the US, with the number of guns (I've seen conflicting numbers between 270 million and 310 million) taking the lowest number of 270 million, if there are 30,000 gun related deaths in the US per year -- that comes to .0002 of guns.
Of course, tragic happenings like accidents do happen. I've read about 3% of gun deaths are accidental, and about 60% of annual gun deaths are suicides. Overall, it seems only a very small percentage -- not even 1 whole percent of guns, not even 1/10 of a percent are involved in deaths each year.
With the figures we see, and the amount of guns, I feel confident to say I think we have more good guys with guns than bad guys with guns in the U.S. I like it that way.