They have existed for too long. The early stages of this world greatly needed such a World Creator, but now that the world is complete, a mad World Creator becomes a burden to the world itself.
This World Creator is just like that.
The burden brought upon this world by the Creator is too heavy, and all creatures upon birth bear an undue pressure, one which affects not only the body but also the soul.
Due to this pressure, the people of this world appear particularly robust, growing at an immensely fast pace; after all, those who do not grow quickly under pressure perish.
This pressure does not target the environment, it only acts upon life, so issues like the land shaking with every step a creature takes do not occur.
Yet, the stronger they become in this world, the greater the pressure they bear, leaving the native creatures like wingless angels, unable to fly.
