Self-published books are looked down on for a reason. I've "bought" some self-published stuff for $0 on amazon. It's pretty bad. It's basically as if the author had an idea for a story, put it down on paper, and submitted the pdf. The stories have potential sometimes, but the writing is just bad. A mix of short 4 word sentences and half a page run on sentences. Descriptions that are just repeated every several pages. Whole books written in the format of: I walked through the door. I looked at the guy. I said this. He said that. I walked back to the other place. I shot the alien. I picked him up. The alien was gross and ugly. I carried him back to the first place.
Just because you self-publish doesn't mean you don't need an editor.
Be that as it may, those are not the people we are talking about here. The topic is published authors at particular publishing houses whining about the retail price placed on their books. Books which they could have easily published, using exactly the same words, without a "publisher."