I don't think it has to do with guns, but more than with the culture of violence that is glorified in America. This nation was founded on the premise of bloodshed and death. Even today look at the blood and gore on tv shows, movies and video games. You don't see this type of violence in entertainment in other parts of the world. You can't really change what is dear to the masses.
I don't think it is one or the other I think the totality of it all needs to be considered Rocket River