but authors get a lot more out of their relationships with their publishers then just paper and glue. They get editing, copyediting, marketing, sales -- we don't just know about Scalzi because the sheer power of his awesome introduced his books to us, after all. Until somebody else is providing those extremely low profit-margin products to the authors, they can't cut off their relationships with their publishers.

You could argue that they can do away with marketing and sales if they meet their fans in other ways, although I would argue that you are wrong. Not all authors are going to be entertaining bloggers, and I know at least one author who started off as a blogger for marketing reasons and then realized that, what with blogging, there was no longer any time or energy to focus on writing.there is a reason that people are hired to do marketing and sales -- it's that they are full-time jobs.

But even leaving that out, editing and copyediting are huge jobs. Every author I know who is happy has a great relationship with an editor and thinks their editor improves their books. Sometimes I know they think their editors also weaken their books because of market research, or fears of politics, and maybe it would be nice if that went away. But even so, they wouldn't keep working with the editors they work with if they didn't think the editors improved their books. So until somebody else meets those business needs, publishers are the ones doing it for authors.