I'll tell you how I know I'm not the bad guy: I never shot first at anything in the whole campaign. When a thrall sparks up peace talks, I'll be the first to sit at table. It is my opinion that the Vex were created by the Traveler as its terraforming agents. The Traveler was ultimately infected by a fragment of the Darkness which then gained the Darkness control of the Vex. The Fallen are scavengers and thieves desiring to pick the remains of earth clean. The Cabal seek control of the Traveler by means of the Black Garden; thus they battle the Vex who are defending the Black Garden. The Hive seek to devour the Traveler and its light. The mistake (or what I'd call a mistake) of many theorists is that they bundle all of the enemies into one grouping and equate "us vs. them" with "good vs evil". The Traveler has power (light) that is desired by each race and will be either granted by the Traveler or taken by force; every enemy faction exists independently with independent motivations for involvement in the happenings of Destiny. These are my opinions, but the fact remains that I never shot first.