I know a number of full-time authors in my position, and we're doing fine in this so-called old school of publishing. Which, ironically, is where many self e-pubbed authors want to be when they get the chance.
I occasionally teach writing classes, and have been exposed to the utterly atrocious self-published stuff that's out there by students who couldn't sell it the traditional way, for good reason. Every so often I come across a true gem of an unpublished writer. And guess what? They almost all DO get published eventually. Because there actually is a merit system in publishing.
The self-published authors you list above, interestingly enough, date back at least half a century ago or more, to the days when many if not most books were self-published. So... where are the amazing artistic writers of TODAY who are entirely self-published? I can think of a number of good authors who started off traditionally published (and whose talents were obviously recognized by the Establishment) who later moved into self-publishing for a variety of reasons. But what about some names of brilliant writers who started off self-published and stayed there?