This is the most recent comment (23 October) I was able to find that Martin wrote about the delay of the fifth book in the series, probably the most awaited book in any fantasy series:

I haven’t lost my enthusiasm for writing A DANCE WITH DRAGONS.

I have, however, lost my enthusiasm for answering questions about it.

And I have REALLY lost my enthusiasm for people writing that I am “not a young man” and speculating about my possible death.

I am not working “only sporadically” on DANCE. But it’s not simple equation: x many hours does not necessarily produce X many pages. Oh, sure, some writers can do that. Not me.

For me, especially on this book, there’s a lot of rewriting (and restructuring) involved. I write a chapter, sometimes several, decide later it isn’t working, go back and rewrite and cut it all out.

These are aspects of the creative process that are NOT FOR PUBLIC VIEW. I am wrestling with my story, my characters, and my muse, and that’s one wrestling match you won’t see on Pay Per View.

Someday I will die, and I hope you’re right and it’s thirty years from now. When that happens, maybe my heirs will decide to publish a book of fragments and deleted chapters, and you’ll all get to read about Tyrion’s meeting with the Shrouded Lord. It’s a swell, spooky, evocative chapter, but you won’t read it in DANCE. It took me down a road I decided I did not want to travel, so I went back and ripped it out. So, unless I change my mind again, it’s going the way of the draft of LORD OF THE RINGS where Tolkien has Frodo, Sam, Merry, and Pippin reach the Prancing Pony and meet… a weatherbeaten old hobbit ranger named “Trotter.”

And that’s about as much as I’m going to say on this subject. Which is probably too much. I guarantee you, I will now get a bunch of letters from those who want to read this deleted chapter. (No. Thank you, but no).

I’m working on it.

It will be done when it’s done. When it is, I’ll let you know.

Why isn’t that enough?

I posted it on Q23 and it spawned a discussion. This is my opinion:

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I think the problem is the diversion, not that Martin can’t write anymore.

Let me make a lame example, take “Lost” third series when they went to tell the tale of two new castaways. The audience dropped sharply and the writers had to cut that plot entirely.

It’s not because that episode was written badly, it’s because it simply betrayed expectations. When you push a “main” plot, then leave it hanging while you go in a completely different direction, people will be pissed. Especially if a long wait (and anticipation building up) is involved.

People wait and wait for the book to come out, then they discover the plot didn’t budge, or was left hanging while it drifted into another direction/distraction. And it means another wait.

This doesn’t work in any media and pisses off people.

Take for example Marvel’s “House of M” crossover, or Glen Cook’s Black Company for something more in theme, or even the first book of Jordan’s WoT. The main plot is resolved within the novel, but before the end more seeds are planted that keep the story moving.

A reader gets both gratification out of the resolved plots and mysteries, and the curiosity and anticipation to keep going and wanting more.

But if you break those expectations, don’t move the plot onward, or delay it to introduce a completely different one while people were awaiting development of the first, well, the formula fails and readers betray you in the same way you betrayed their expectations.

The MAIN mistake, here, was made by the editor himself, who convinced Martin to split the book. If he had forced Martin to keep it as one book, and cut down the word count and superfluous storylines, AFFC could have been a worthy book, on par with the other three.

P.S.
Of the whole series I’ve only read the first prologue. Still, my analysis is precise.