Very cool, if true

I'm not sure what value the publisher adds to the chain though (marketing and a nice cover?).

Um, publishing? Talking to the printer, getting your book to reviewers, getting it to distributors, arranging for it to appear in good places in shops, and taking the hit on the cost of all of that, so that the author doesn't have to pay to get their book onto the shelves?

Of course, some of that goes away with ebooks. And all of it goes away if you only want to appear on Kindle. But if you don't want to end up with a monoculture then you're going to want your book to appear on more than just Amazon, and that means dealing with distributors at the very least.