I see the value in two ways, neither of which, in my mind, is a benefit to a published writer:

1. It gives you an (artificial) deadline. Without a deadline, some aspiring writers tend to say “I can start (whenever)” or if they’ve started, “I can finish (whenever)”. Of course, (whenever) never comes. If you’re a published writer, of course you don’t need this because you have REAL deadlines.

2. It gives you an excuse to everyone else you deal with in the world as to why you are sitting down and writing and not doing any of the other hundred things that demand your attention. Again, if you’re a published writer, you don’t need any excuses – it’s your job to write. But if you aren’t a “professional” writer yet, everyone assumes that literally everything else in the world should take precedence over your writing. At least that’s the case for me. With NaNo, you can say “It’s just for this month. Whatever else I have to do – don’t worry, I’ll get to it in December.”

As for submitting in December… please. I’ve only submitted two of mine, both more than a year and multiple editing passes later.

I’ve written this way in a lot of things. I had a published short story (flash piece) that I wrote in about an hour, maybe two, and edited over two days. Very few changes. I’ve done that with a few pieces.

If I try to edit along the way, I’m pretty sure I’d never finish (especially now, since I’m in the mucky middle of a novel–all I want it to get through this part to the end!)

I know when I’m “done” with the novel, I’ll have a metric ton (or twelve) of revisions, but that’s okay. I get the feeling I would anyway. The story changes as I write it, and I just keep plugging away at it and make notes for later changes. It is working for me at this point!

I still have about 30k to add to my Nano novel, and whether it’s a first draft for me or not, my writing improves the more I write and the more I learn. This draft for me was better than my last “polished” novel.