Yes, it's true that if "they" put their work online it would impact sales of the book.

Of course, if people fax pages of it to each other, that would probably impact sales as well... to say nothing of ingringing on their copyright.

So, I guess what you're saying is that it would be a mistake for the rightsholders of the book to share it with the public, but that it's okay for you to do it.

Makes perfect sense to me.