Uhm, you do realize that the Traveler's 'Light' is essentially magic, right? It turned Mercury into a Garden World despite the fact that it's surface temperature is 700 degrees and it's so close to the sun that anything living should be fried by radiation. Destiny isn't straight up Sci-Fi, it's also got major fantasy elements. As for the Awoken, you're assuming that the Reef has always been what it is now.