Something I dont think many people here understand is cost. Ideally, businesses want to get the most for less. The designer drafts several layout ideas, and then they discuss the options with the client. What's the best, optimal solution? What's the most marketable?
More likely than not, there probably were older drafts that took up the entire original layout. They were probably more expensive. Think Texas Giant - they cut out the helix, and no excitement was really lost from the ride.