It seems to be the general consensus that self-publishing means one or two gems amongst a million badly written and unedited books.

Of course, the fact that seems to escape these people is that "real" publishing means one or two gems amongst a million badly written and unedited (or underedited) books TOO. Because even established authors can write turkeys (especially if they achieve high-income author status and start getting shirty about being edited), and even "real" editors can pick out howling turkeys, or just horrendously mediocre work.