Someone who was really writing 2000 words a day every day (or at least on average) would be creating 730,000 a year. If you think about the length of some of King's works (The Stand is 486,000 words, for example), that could be as little as two books, one to publish that year and one to save or later. I suspect it's more like two drafts of the same book, but I haven't seen the program or read King's memoir, so I'm not sure whether we're talking 2,000 completely unique words each day or whether second and subsequent drafts also count somehow.
Anyway, a lot of the people who release really rapidly write much shorter books. I'm reading someone's box set right now. The books are good, and each book has a complete story arc, but they aren't very long, probably not more than 50,000 words (a novel, but close to the low end on word count). At that rate, 730,000 words would be the equivalent of about 14.6 books per year. If we assume a writer needs to do two drafts, and that those drafts probably aren't complete rewrites and take about half as long as the first draft, we're down to about 10 books. In other words, if Stephen King is accurate in stating his daily word count, if he were an indie writing shorter books, he could be producing 10-15 books a year.
2,000 words a day sound doable, but of course, other aspects of life sometimes get in the way. Also, some of us have a hard time pressing on right away when we're stumped. Also, some of us produce more complicated plots that can't be handled in 50,000 words. Double that would end up with 5-7 books per year, still fairly substantial.
All of that said, I find I need to reread a few time more, even with an editor, to make myself satisfied. We all have different patterns that work for us. Some allow for higher production levels than others. I'm at peace with the fact that I'll never be a really fast writer, even thought that 2,000 words a day sounds doable.
Oh! I just saw YouMeWe's post. Yeah, this is an old thread. Yet the issue still lingers...