I know what you mean but I’d call that another symptom. Anyone who shoots another person in a rage has mental problems that go back a long ways. Which brings us back full circle; firearms are not the problem.
Good point, if a person is that mentally off, they would use any means, a knife, choking, not just a gun.
But it does seem like most partners are lunatics, not spouses of a decade or so. It doesn’t seem like people are making healthy decision with their lives anymore. Not being very judicious in their choices. Probably because relationships are all throw away now. Just like all the Chinese stuff.