GRRM doesn't owe me anything. This is an entirely true statement. But by the same token, I don't owe him anything either. He's written a series in which I've invested my interest, and I'd like to read and/or see the end of it, to see how it turns out, and that is the extent of my loyalty toward him. I owe him nothing more. And to be entirely honest, the guy seems like kind of a dick, so I don't really understand WHY I'd want to invest in him any more than that. But perhaps recent statements are just a result of him being constantly hounded for years on end, and perhaps I would react the same way under those conditions, so I will reserve judgement on that point and give him the benefit of the doubt.
GRRM has said multiple times that if he dies, the story goes with him to the grave, he would not allow anyone else to ghost write it (ala Wheel of Time). In this, he is kidding himself. The story WILL be finished, either with him or without him. This is known. If done without him, this can be done either officially through an actual writer using notes he has left, or it can be done by 5,000 rabid fans (most without any shred of talent) writing competing endings and throwing the entire thing into a cluster fuck of epic proportions. Apparently, according to GRRM, he prefers the latter, which to me is absolutely mind boggling[1].
So the only question is going to be: Does he want it finished the way he intended, or does he want it finished under someone else's reigns. If he wants to finish the story himself, then, for his own sake (not for mine or any other fan), he needs to light a fire under his ass and get it done. Because yes, he is a fat guy going into his late 60s. And at this point, the odds are not so much in his favor for him making it another 15 years. Sorry George, you can "Fuck You" to me all you want, but I gotta calls em like I sees em.
[1] This series, at least, has the advantage of the HBO adaptation, and presuming D&D are allowed to finish to the end, that will probably end up being considered the cannon ending should GRRM not be able to finish it himself, and no doubt there will be a reverse-adaptation (novelization) of the series by somebody (hopefully with some writing talent) so that those of who prefer to read the story can do so in time.