I think this is caused by lack of education. Parents that own firearms should be training their kids at a young age about firearms safety, and the dangers, responsibility, and moral sense required when handling firearms.
Maybe schools should teach courses on firearms safety and the dangers associated with mishandling of firearms.
In the old days ROTC taught these things, if I am not mistaken. I never had that opportunity, but this is what I have heard.
But I fear political climate and correctness would make such a thing an impossibility.