The was originally going to be a Facebook post, but word limits are annoying.
A bit of background on me and NaNoWriMo. My first NaNo attempt was back in 2006. Wrote 30k words and then lost steam. 2007 was about the same and interrupted by a week of the death flu. I still can't eat at a certain Mexican restaurant because of it. My first "winning" novel  was a three part story that I ended up lopping off the start and ending sections and working on the middle to expand. Never finished, but I still have it for future work. 2009-2011 efforts were mediocre at best and not really focused all that well. I could mine them for ideas, but at the basic core, not something I'd work on to expand. 2012 was a series of interconnected short stories with the theme of superhero/villain origins.
Below is an article that came across my twitter feed [@simms.doug]. A different take on NaNo. I agree with some of what she says, but for me, it's about the approach. You aren't going to write a perfect first draft. Not everything you write is going to make it in or even survive the first edit. I'm not a professional novelist. I might never be. But I like the challenge. Sit your ass in the chair and write. I can crank out 1700 words a day. Might take me 2 hours, but I can do it. If I'm on a roll, that's an hour of work, but I'm not a fast writer. Like her, I have to stop and think about what I'm writing. I don't see that ability and doing NaNo being mutually exclusive.
The local group had a Thank God Its Over party. One person admitted they hadn't reached the goal. Did we view that as a failure? Nope, we encouraged her to keep going and try again next year. I think she's reading too much into the encouragement that participants give out. For me, it's the effort and willingness, not necessarily crossing the finish line. It's not a given that I'll finish next year. Even if I don't, I'll have something that I can springboard off of. One of the stories in last year's effort has been divorced from the supers theme and become more of an urban fantasy story. Much darker and nasty than anything I've ever written before and since.
One thing that I will agree upon is that it's not for everyone. Some people don't need it or aren't the right fit. For others, it's the perfect vehicle to get them rolling on an idea. I fall into the latter category and enjoy the hell out of the experience.