Sarcasm aside, guns are a tool with multiple uses. Many use them for target shooting competitions, others because they hunt for sport. Guns are also a tool for self defense, a very effective tool.
Yes guns are capable of killing people, that's why they were invented. But that does not mean that giving a citizen a gun makes them a killer. In fact, studies have shown that the responsibility of carrying a gun makes one less likely to get into confrontations in the US. For example, citizens in Florida who are given a license to conceal carry in Florida have a very low crime rate. Since 1987, over 258,000 people in Florida have received a CCP, out of that population, only 18 people have been convicted of a firearms violation. That's a crime rate of .006 percent. In addition, in the many years since Floridas CC laws were passed, its crime rate dropped 22 percent, while the national average (mostly restricting guns further) rose 14 percent.
I will repeat my original point, just because guns were invented for the purpose of killing, does not mean that giving a person a gun makes them a killer. It's only those people who decide to abuse these rights, or those people that have proven to have violent tendencies, that should be restricted with their gun ownership. We should make sure others are allowed to own them, just in case one of these for mentioned psychos decides to become a killer, and they don't need a gun to become a killer.