The facts are free already even if I choose the most restrictive use of copyright around. Fiction is different. The argument for open sourcing fictional characters is much stronger. Many of the major studios and content factors look the other way when fans write new stories with famous characters. There is also a permanence to a book that is strikingly refreshing.
Webpages are just too mutable.
At times, this can be slightly creepy and pretty Orwellian. I can think of several times where the old text disappeared and was replaced with the new text. Alas, dead trees and ink cost money. The main advantages that flow from sharing the source code just don't apply to text. Sure, it would be nice if I was rich enough to give away the book, but I'm not.