What is an editor?
When I was a PhD student, I copy-edited some articles for a professor. When I did this, I checked every footnote - by which I mean, I found the book in the library, checked the wording of the quote, checked that it appeared on the page referenced, checked the publication details of the book. I later discovered that other copy-editors doing similar work did not believe that to be their job. They just looked for stray commas.
The differing expectations of editors are something I came up against later, when I hired a copy-editor for my first book (this was not something the publisher would do). In the manuscript, I had misspelled the name of a scholar I quoted. The mistake was mine, but I (naively) had assumed that hiring someone to proof it was some backstop against that kind of thing making it to press. The copy editor missed it. Later, someone who wrote a negative review of the book did not.
The copy editor I hired was in fact an un(der)-employed academic, and since then I have noticed a trend. Humanities academics offer themselves as "editors" without necessarily any skills or training, or even experience, in editing the work of others.
So I was interested to read this excellent piece, by a professional editor, about the sliding standards of book editing. I know I'm not the only writer who has been expected to provide my own copy-editing services for an academic book, and the results are not pretty.
And that's beyond even having someone at the press who will EDIT a book - such as, tell you that chapter three should be excised, that the section from p.58 should be brought forward, and have you thought about adding a bit more about President McKinley? When I write for magazines and websites I've received that kind of editing, and been grateful for it. I've never had it for a book. Certainly not from the person whose job title is "editor" at the press.
The only good experience I've had hiring editorial help was actually with an indexer. She worked on my second book, and was wonderful. Worth every penny. Hire her (Laura Knox).