You’ve made a sound argument against owning cars and table saws and boats, not one in favor of owning guns or that they’re safe to have in the home, especially in the face of overwhelming evidence.
And what you think is irrelevant; the facts speak for themselves. All you’re saying is that you’re choosing to ignore the facts, ignore reality, because you think you somehow know better. And regardless of your attempts at rationalization, it doesn’t take much to figure out that, without a gun in the home, this person would have found it far more difficult to so quickly and instantly murder his whole family and then himself, and family members would have had a much higher chance of survival and/or escape.
Even faced with the prospect of the much more difficult task of killing his whole family by other means would have greatly reduced the likelihood of him following through with his plan at all. With a gun, it’s all so easy. Using some other means makes it more difficult a task and is enough to give a person pause— often just enough to change a mind, to create an opportunity to seek help, etc.
But you’re not even willing to consider any of that. Because of boats and cars and table saws…
BTW, getting a license to drive a car/boat is much more difficult in most states than getting a gun license. And I don’t know of any stories of families being mass-murdered or schools or nightclubs having everyone inside them being slaughtered by table saws.