It's why, as much as I enjoy it, I will NEVER play hardcore mode in Path of Exile. In a normal league when you die, all you really lose when you die is time. That's annoying, but recoverable.
But yeah, I really don't understand why GGG hasn't ever given players a tool to find out what killed them. With all the complexity that the game has under the hood, why not this? It makes very little sense.