Why are scriptures often allegorical?

Nayaswami Gyandev

Question from brock: If the scriptures are allegorical or symbolic, why did the authors choose to write in this complicated way? Why not just spell it out like it is done in the contemporary books? I would think the saints would want to be compassionate to trees and save lots of paper that would be used on interpretations, and alas, misinterpretations!