The Nightfall strips away everything except the question of whether you are good enough for the task. No matchmaking, no margin for error, the modifiers stacked against you in ways that make the standard activity feel like a memory of safety. The Insight Terminus is a Vex installation and the Vex do not care about Guardians — they are not enemies in the dramatic sense, they are a system encountering an obstacle and processing it. The Ghost brings you back when the system wins. It does not explain why this particular Guardian gets to keep trying.