Macbookair trackpad

I do a great deal of writing on my Macbook air. One thing I DETEST about this laptop is the trackpad. Why, after so many complaints, does Apple not have a simple setting to turn the TRACKPAD OFF OR ON? When I type, I continuously have to use control z to recover my location in my writing when my hand brushes over the trackpad. This is a HUGE FLAW in this machine. such a simple setting and Apple does not have time for it, even though we pay APPLE thousands of dollars for their equipment. Disgusting.