Lately, I have been working as an editor for a friend who has an amazing gift to put words on paper. His gift primarily is to do so in massive amounts, but he's also pretty fucking good for someone who is an untrained writer who jumped head-first into writing a two hundred page novel.
My assignment here started as just making the work he had already done more readable, and formatting it in an acceptable way to be sent to a small scale publisher. However, I no longer feel this is doing this friend justice. His talent, and his story deserve more than a little sandpaper. Here is why:
A writer does not need to agree with his editor, and the editor with the writer, either. But, the writer should know enough about craft, agreed with or not, to defend his work with the editor, with the publisher, with the critics. A writer worth his pages knows why he did something this way, and not that way, and more importantly should be able to argue his correctness. And even if that writer does not win that argument, plant a seed of doubt in his detractors. That writer should know why people he disagrees with do the things he disagrees with. That writer should know the rules he is breaking or following, and how they are being broken or followed, and why.
The editor is only around to push the writer, make the story better, but remain invisible in the finished product. Your editor cannot make you a better writer, but he can point you to your strengths and weaknesses.