This is the latter. In fact, it's the principle behind all of editing, IMO.
One of the things I most hear writers say (myself included) is how characters run away with the story; I personally have described my writing process as excavation more than creation. When you're delivering that first draft in particular, it's natural--normal, I think--to feel you are a reporter or a scribe, following the characters wherever they lead, barely seeing ahead of you like the headlights of a car unable to permeate the dark, foggy road on which you drive.
The problem comes afterward when this is used as an excuse for any criticism: "That's just the way my characters are/I didn't control where the story went/etc."
It is fine to be a scribe for the first draft, but afterward your role shifts to that of messenger.
Before you can revise, before you can get critiques or edits, you need to know what you are trying to convey.
You need to know what motivations drive all characters, not just your POV ones. You need to know how you want your reader to feel about the world, the people who populate it, and the things they go through, and this is true for all aspects of the story. Your job is to communicate with the reader.
This is why grammar and spelling are important: following the "rules" doesn't make you less of an artist, it makes you more effective at communicating. Giving your work structure doesn't lessen the artistic merit of the work, it makes the story more palatable for the reader. Ensuring your heroine's sympathetic qualities are clear on the page isn't changing your character, it's making the reader root for her the way you do. Cutting (or adding) scenes for pacing isn't murdering your baby, it's to keep the reader engaged.
I can't tell you how many times over the years I have seen writers refuse changes requested for clarity's sake because they insist the characters are just behaving the way they do and they don't really know why, and that scene must stay there although it advances nothing, because they are ARTISTES! DAMN IT! Like somehow delving in and knowing what it is you're trying to communicate lessens the magic of storytelling.
Sometimes it's laziness, but other times I genuinely think writers believe this: that crafting, during revision, and taking things apart to ensure they're put together right kills the soul of the work. But it does quite the opposite, and while you can certainly over-revise (more another day), what normal revision does is allows the reader to see the soul as you do.
Otherwise this story that you have worked so damn hard on is just a big, shapeless lump that isn't pretty and that people can't understand--you have to speak for it, and you have to do it effectively.
|Like the Log Lady in Twin Peaks.|
Because that is your job when you're in it for publication. Readers pay your bills; readers drive the industry. And they don't live in your head, they don't know what you know, and your ability to communicate with them is just as important as the story you are telling.
So your first step with whatever your revising is to break it down scene by scene, character arc by character arc, sentence by sentence, word by word, and ask yourself, "What am I trying to communicate here?"
If you don't know, I'd suggest taking a long walk just thinking about the story or talking it out with someone because you can't go any further.
If you do know...now the real work starts.
photo credit: hippydream [is busy] via photopin cc