nospam007, can you name me a dozen self-published authors you read regularly? Half-dozen?
I'm honestly hoping the answer is yes, but I think it's likely the answer is no. (Or you're a heavy fanfic reader, in which case as long as your tastes don't change, you'll do just fine.)
Anyway, my point is that it's not the editing (okay, the editing is really, really useful), it's the acquisitions.
Of a 1,000 books on the slushpile, about 10-20 are what I would call "publishable". i.e. they've got a decent shot at being enjoyable. (Books outside of that range might have an outside shot at being enjoyable, but are essentially part of the "million words of garbage" that each author needs to write just to get good enough at their craft that they have a chance at being successful.)
So, the primary job of the publisher/editor is not so much to refine a book, and to act as the filter. Without them, I'm almost certainly spending at least 10 times as much time to find a book that I enjoy as much as I do now.
And when the enjoyment/time ratio goes that low, I stop reading...
And we see this. There are probably 10-100 thousand books self-published each month. How many new authors from the self-published world make it onto the radar of even a low midlist writer. One a month? Two? And it's not that there's not good stuff out there in the self-publishing world - it's that there's no means of discovering it without reading the hundreds of not-yet-ready-for-publication books that no-one wants to read without being paid for it.
I'd love to see self-publication become a viable option. But better brains than mine have been trying for years, and the best they've come up with is something that's going to be a pale shadow of the size of the current industry, read by a societally insignificant number of readers.
That's why I'm not optimistic for the book industry's future.