I get why it's frustrating but think of it from Universal's standpoint: by most accounts, scareactors "clock in" at about 5PM to get into makeup and costume in time for the event to begin. If their cast's shift is running until 2AM(or later, really, not everyone in line before the cut off will make it through before 2AM), they're already working a 9-hour shift. Casts A and B both get 45 minute breaks all night for touch-ups, food, and resting their feet and voices, they alternate between A and B but one shift gets off 45 minutes before the event ends. So hypothetically the last shift could get stuck working over their allotted time in the houses and running themselves ragged in the process. The guests probably wouldn't enjoy themselves with a tired and overworked cast. Like I said, I know it kinda sucks, but it's for the benefit of the scareactors, staff, security, and guests.