It's simple really:
Guns have no morals. Guns can protect and guns can harm, it's the user behind the weapon that determines the outcome. It's almost as silly as saying spoons make people fat or cars make people drive at unsafe speeds.
Now ponder on this:
Let's say guns are outlawed. Just like moonshiners back in the day, guns will still be created and sold underground.
Now, let's say that you are in an auditorium with 1,000 people. One criminal pulls out an AK and starts shooting everyone he sees. Now, you must rely on some official with the rights to carry firearms to protect the community. Well, what if there isn't one on site? What if there was two or three, but the criminal watched them and made them the first targets, leaving the rest of the people defenseless? What a bad day that would be.
Now take this same story, assume guns are not illegal and that 1/10 of the population (100 people) had firearms with them. Given the same scenario, which story would you expect to have more causalities? Hopefully you came up with the conclusion that more firearms to the public would create a safer living standard for all.
Also keep in mind that if guns became outlawed, it gives incentive for guns to be distributed more rapidly by criminals underground. The reason is that they can make a great deal of profit for selling something not easily accessible to the public, just like marijuana in some states is today. When marijuana became legalized in California (with a license) it ran most marijuana drug dealers out. It just doesn't sound reasonable to ban guns, when they have no morals, they are used to protect (90% of the time), and the cons can be detrimental to society.
1. No system is safe.
2. Aim for the the impossible.
3. Have fun in cyberspace and meatspace.