Completely off the wall and not supported by current lore at all, but a "would be interesting if" type idea: The Golden Age scientists experiment with immortality, create robots made from organic stock under the premise that it could accept organic memories, end up creating original Virtual Extension (VEx) robot prototypes from Radiolorians. These become proven as not viable for human mind hosts, so the scientists go different directions and eventually make Exos, initially using militaristic models based on historical precedent and utility. The Vex robots are converted into computing devices to advance technology instead and networked together into "world-minds." This becomes the advanced model for computing and different types are used for various ends. In the meantime, other scientists make a device to "lift the veil", realize human minds can't comprehend it other than scattered impressions of impending doom. This leads to learning the nature of the darkness, leading humanity to advance their minds for impending war (warminds). In their desire to understand and divert the disaster, they send the vex prototypes into the veil as explorers to find a way to ensure human survival. There they remain with their directive to find a way for humanity to survive any potential outcome. over time, humanity forgot they existed. They learn how to cut through the veil from Crota, learn about the Traveler and Sword Logic from Oryx and develop the confluxes, vault and proginy in an attempt to gain strength to overcome the Hive which is the main perceived threat. However they copy the hive in order to defeat them by worshiping the darkness, becoming a threat to humanity themselves, which is where we find ourselves today.