[Monster Inc.] The Generator

This is my first "fan theory" post, so I do hope this is the right place.

In Pixar's Monster Universe, it was essential for the monsters to obtain their power by screams/fear.

These monsters created a way to teleport into kids closets..

Why not the maintenance closet at Hollywood's Tower of Doom, you got an automatic fear collector at the bottom of the attraction ... There are tons of ways to get fear. They went with kids closets.