When these civilians first fled, the people of the sacred Institute didn't take it seriously. In their eyes, those people were just civilians. If they ran away, then so be it. They could save some food.
However, they soon paid the price for underestimating the civilians. After the civilians fled in a large scale, they left behind only pieces of empty land. There was no one in a hundred miles. It was not an exaggeration to describe the fleeing civilians.
At this time, the people of the sacred Institute found that once all the civilians ran away, there would be people planting food for them, and no one would weave cloth for them. They then realized that they couldn't live without these people.