In my opinion, when one publishes a work in which millions become emotionally invested, one has a moral responsibility to finish that work if possible. GRRM more had the time to do so, and did not.
I’m sorry, but even a book that falls short of expectations would have been far better than no book at all.
Writers write not just for the fame and money it *might* someday bring, but because we *must* write. Writing is the loneliest profession; the stories must be told, and we cannot deny their call.
As was already pointed out, GRRM is a successful author, but it strongly appears he is no longer a writer.