This goes way back into the olden days. Items stuck on the ground (such as two-story statues, etc) spawned there every morning during server up. Before server down, you used to be able to litter the ground with a punch of wooden boxes, so when the item spawned, it had no place to go other than into the box. Because they're unmovable, it essentially became "stuck" in the box until you axed it, in which place it drops to the ground where the box used to be.