If you think the solution to that way of thinking is for someone to die, that's like thinking the only way to learn about the dangers of a hot stove is to burn your hand on it.
I mean, I don't disagree (though I think you're mischaracterizing his post--he didn't say it was a problem in need of a solution, he was merely saying that death has that effect), but it seems like your example is counter to your point.
Maybe, someone, let's say, a parent or guardian, telling you that touching a hot stove will burn you, and you taking this seriously.
The tone of his post seemed to me to indicate that he was generally insensitive, and only the death of a loved one could snap him out of it. If he had enough empathy, he would have learned more early on that he should be more aware and respectful of others' feelings.
Well, I've never been shot either but I still think I'd rather not ^^;