I live in Metro Detroit. The murder capital of the US. And guess what, in the 13 years I have lived here, I have not seen a single gun being used or brandished. If someone holds a gun to my head, they want something. Most likely money. I do not feel that getting killed over, or killing someone else over the $200 in my pocket is worth it. They can have my money.
Sure, in your lifetime you could happen upon the crazed gunman in the mall scenario, and then you get to act out your Rambo fantasy in real life, but you have a better chance of winning the lotto twice than you do of that occurring.
IMO, more often than not, guns will unnecessarily escalate a situation that could have been diffused through using common sense.
The wild card is home invasions. I 100% see the justification for keeping a gun at home. That is your castle, and that is your family, and if someone breaks in to your home then all bets are off and deadly force is justifiable.