This "sweat of the brow" argument doesn't cut it. Books have long been unprofitable for the majority of writers. At the same time, it's now easier to publish than ever -- look, I'm doing it right now! The question here is should publishers be allowed to control and make large profits (the authors weren't in any case), and I think the answer is clearly no.
This. In addition, if we charged to the "value" of a book, then only shitty magazines will be available to the masses. Doesn't seem like a great formula for spreading said "great content".