I had always had the idea we are going to be at war with the traveler. The speaker is evil and basically selling out the solar system to protect himself The "gods" of the solar system. Crota dlc/hive control power over the moon the traveler needs the power so basically is sending the guardians to do what he can't. The traveler created the ghosts to search out worth fighters to cart out his needs basically eliminate the powers that protect or control what the traveler can't. Eventually we figure it out and end up fighting our ghosts At the time when the traveler is close to taking over and we are about to fight him the speaker basically turns on the city/ guardians. And Rasputin and dead orbit and fwc become the protectors we destroy our ghosts and start our mission. Guardians are suppose to make their own story and that only begins when we figure out what's truly destroying our world.