I too had this thought the other night laying around reading lore. We are like Oryx in the fact that we cannot die outside of our realm (earth maybe) as we were resurrected by "motes of light" (i.e. our ghosts). We learn to fight and defend knowing ghost will revive us and we do this almost blindly. We can even resurrect ourselves, I'm looking at you warlocks. To be honest, to me, the story of Oryx and the struggle for death and the spread of the Darkness is a mirror story of the Struggle of our Traveler and the survival of Light. It is the classic good vs. evil story. It shows that it is much easier to be the dark (as evidenced by the vast spread of Oryx's darkness and mass species extermination) than it is to be the Light. All we can do is speculate, as we don't have the answers. But your comparison, while might not be taken as literal as the asshat that is giving you crap states, it is a VERY real duality of the Destiny universe. I just wish that this lore was more integrated into the actual game....maybe one day.