I agree the Traveler is not "evil". The Books of Sorrow make it pretty clear on what the "evil" in the Destiny universe is. However that does not make the Traveler "good" either. In the past it has abandoned species in the past when it was clear the Darkness would win leaving them to die (this was the case of the Fallen). It would have done the same with us if Rasputin hadn't stopped it from leaving, forcing the Traveler to make Ghost to find Guardians which gave humanity and the Light the greatest chance of standing up against the Darkness since the fall of the Fundament.