I actually just wrote a reply regarding this on another post. Part of the theory the OP pointed out dealt with the darkness turning humanity against itself during the collapse. That being why there is no evidence of dead enemy combatants from the collapse....the enemy was us, corrupted by the darkness. I found that bit of the theory very interesting. The whole idea of the darkness turning us against ourselves is very cool due to the different ways one can interpret that action. To me, if this holds true, then the whole story of Destiny could be an allegory of sorts detailing the nature of man. Mankind as a whole has an inherently dark or evil streak to it what with war, murder, etc. This allows for the jump to be made regarding the darkness not just being the big bad enemy but something inherently woven into every species it comes into contact with. At the same time though, this allows for a cool twist on the traveler. Rather than the traveler bring seen as this shining beacon of salvation, one could say she's more a physical embodiment of the inherent good in mankind. Teamwork, comradory, empathy, love, etc. If you take the darkness and the traveler in that sense, then really Destiny boils down to the constant struggle humanity faces pertaining to cooperation and strife. The latter being what happens when you give into the darkness and the former being those who choose to live by the light. I don't know, but I'd personally like the story to have a cool deep and impacting meaning like that when all is said and done.