W,R, how about this example?
It's what I see as a helpful rejection from an agent. Said agent, who'll remain anonymous, drew my attention away from my writing and to my story telling - something a couple of other agents had hinted at. This agent explicitly described what she saw as the problem with my book proposal in a way that I found useful. The story I'm telling is true (that's truthfully-true, not Frey-true/ Seltzer-true). I thought that my story's narrative drove itself, but it seems books aren't quite so simple.
The email, rejecting:
Dear Peter Corkeron:
I read your material with great interest -- I learned a lot and was amazed at what a wildlife biologist has to do for a living. However, I don't think you've got a good grip on how to tell the story. I found it hard to follow and had too many questions about what was going on -- or who was who -- to think I could interest a publisher in it. I think you have a gift for description and you're writing is lively. But that's not enough -- I think you've got to craft a really strong narrative to make a book like this work for the general public. It's really a matter of learning technique, I think, since you write well.
I also didn't think the proposal with its strong polemical message matched the story you were telling. In any event, I think the way to handle an argument like this is to involve the reader and make him or her care about the seals and their environment. Then you can slip in the polemic while they're not looking.It may make sense for you to work with a professional book editor or perhaps just to study up (in a course or with a book) on how to tell a story. If you do work on it along these lines, I'd certainly like to see it again.
[A kind agent]
P.S. And [short, shameless plug here] if anyone wants to read what she's talking about, browse http://aleakage.blogspot.com/ The right-hand sidebar has a section "Stories of fieldwork" - three chapterish thingies are there. Or try "Eclampsia" in "Preeclampsia Pieces."