I can't decide who's the bigger asshole: The tree or the kid.
In thinking about this since my childhood (I wanted to punch Shel Silverstein's classic in the face even then), I have never figured out what all the precious fuss was about.
While some claim this book is about unconditional love, to me it smacks of a cautionary tale heard over and over again in twelve-step programs. In addition to being a playmate (branches to swing on), a protector (shielding the kid from harmful rays), a provider (offering up its fruit for food, branches for a house, and trunk for a boat), and a stool (finally a stump), The Giving Tree is a sap.
Plus, the tree is female, which makes her continual sacrifice to this knob even more annoying and questionable.
Might I suggest that this parable serve as a lesson to all the other anthropomorphic trees and shrubs out there. Set some boundaries, learn to say no, and get your Serenity Prayer on. Accept that you can't change greedy, thoughtless little shits, muster up some courage to change your behavior and drop an apple on his head, and get wise to his ways. That's the path to happy, joyous, and tree.