I am elbow deep in content editing for Recompense right now, and tearing out my hair. The problem is knowing what to carve out. It's not simple.
For instance, one review site gave Athame a generally very good review, with the single complaint that I did not include enough background material on the characters and world. Another, a private purchaser, left a good review on Amazon that liked the early part but thought the book got a little too bogged down in detail in the latter half. A writer can't win. What one reader loves will provoke another reader to gripe.
The standard so-called wisdom for many years has been that anything which doesn't advance the plot, or add necessary information about a major character, should not be in there. "Murder your darlings", etc. But then you get readers who like to savor the immersion factor and complain that the story feels rushed if you don't toss in a lot of texture. Times are changing also, with the increasing prevalence of electronic books and self-publishing.
Big publishing houses that put out large runs of paper books have a vested interest in keeping a book size down as much as possible. Partly to control production costs, partly to minimize losses if it doesn't sell well and they have to take it back for disposal. That doesn't apply to digital media. There are also several recent surveys that show people are tending more and more to prefer longer books. Maybe folks are starting to enjoy immersion more. Or maybe they just want more book for their money, given the tight economy. Or maybe people have always liked long books, and the publishing houses just kept readers on a starvation diet.
But by the same token (cliche anyone?) nobody wants to write another Robinson Crusoe. To anyone who hasn't read it, RC was a torturous ordeal to wade through. Verbose does not begin to cover it. It actually doesn't have a real plot as such. It's not actually about anything. Just an endless stream of consciousness plus soapbox for the author's philosophical musings. Thankfully, almost no one reads it anymore. I have no idea why anyone ever did, to tell the truth. It really and truly sucked. No personal offense intended to anyone who loves the piece of crap.
I am told that my main flaw as a writer is my tendency to digress away from the main plot into irrelevancy. Hence, I am deeply concerned about making sure that everything left in a book is clearly relevant to the book, with the possible exception of minor foreshadowing that will be left as hooks for the next story in a series. But what to cut? Which darling do I murder?