One of the things that distresses me about being a self-published author is that when you surf around you will find lots of the same advice repeated over and over--specifically that you need to (a) hire a great cover artist, and (b) you need to hire a great editor (and sometimes three of them) to make sure your manuscript is in perfect harmony with the planets as they align. While I have nothing against these two pieces of wisdom per se, the problem is...self-published authors are what we call in the vernacular..."poor."
See, artists and editors don't do their job for free. Who would? They provide a meaningful and valuable service, but the truth of the matter is, the cheapest I've seen for either of these two fields is $200 a pop. That's a total outlay of $400 per book just to upload it to KDP, or Kobo, or Pubit!, or Smashwords...
Take that number ($400) and compare that to the price of your average self-published novel, $2.99, and you see that you need to sell 134 copies to even break even. Most self-published books, everyone will tell you, never sell more than 500 copies; and the majority of them sell far less than 200. The odds are stacked against you from the get-go.
What we need is a bunch of people, editors, artists, document layout experts,...the whole gammut that is needed in the publishing world...to offer their professional services cheaply, or even better, freely.
That's not going to happen. To steal a quote from the Joker: "If you're good at something, never do it for free."
For editing, you might say "Beta readers," and they are a help in many ways, yes; but few of them have the requisite grammatical knowledge (like a BA in English) to be of a "real" help. Believe me, they do help quite a lot, but a real editor is a thing of sublime beauty. Something we sorely could use.
Artists and graphic designers are the same. These magical creatures are special, rare, and expensive; and I don't know any that will do the needed work with quality for free. We're lucky if we manage to get a decent cover at all since we're more-or-less stuck with going it alone.
So, when you read a self-published book and find some grammatical errors, or the cover just plain is terrible, keep this in mind: self-publishing is hard. We don't have a big corporation behind our work, helping us at every turn with marketing, management, style, layout, covers, editing...and all that it takes to get a book from "A" to "B"... There's just us.
Am I asking you to cut us a little slack? Yes, I am. But not when it comes to the story, that you have a right to critique...but all the things that we're now "expected" to master...not so much. It's a tightrope I'm asking you to tread, and honestly I don't envy the walk, but along the path I believe you're going to see some amazing vista that would otherwise be hidden from view.