The Carver and the Mangler

I waited five, terrifying, minutes, then followed. I thought my heart beat so loudly that everyone heard it up and down the tunnel. I got to the side passage. I saw no one along its whole length. Did someone slaughter my friend and spirit his body off? That side passage ended with a door. The light came from that door.

Carcass with a Cape

So, why did the Intelligences go through so much trouble to recreate Earth’s life and human civilization on Terra Beata?