However we try to spin it, a gun is not a teddy bear.
It is a device that projects something hard at high speed with some degree of accuracy. That makes it very efficient and effective for damaging things -- whether what is damaged is piece of paper, a clay disk, a locked door or living flesh. It is a means of projecting force.
Those properties make a gun useful for recreation, putting food on the table, forcing one's will upon someone else and defending against victimization.
A gun is a tool that makes a person more formidable. If he's an evil person intent on crime, it increases his power to do evil and further his criminal desires. If he's a good person, a gun increases his power to defend himself and others.
A gun is what it is. Debating whether it was designed to kill leads nowhere. The real issue is that it is something that can be useful for ordinary people to have and know how to use; it is something that has been useful to ordinary people; and it's something that ordinary people have used responsibly for worthwhile purposes.
"It is long been a principle of ours that one is no more armed because he has possession of a firearm than he is a musician because he owns a piano. There is no point in having a gun if you are not capable of using it skillfully." -- Jeff Cooper