George is a free human not a slave to our desire for _content_, also true.
But I also understand fan frustration. When Gaiman wrote that, "A Game of Thrones" was already 15 years in the past. "A Dance With Dragons" had been promised for 2005-ish and was still 2 years in the future.
Since "GRRM is not your bitch", George has published 10 books, of which one advanced the core story of ASoIaF. Meanwhile, on his not-a-blog, George's infrequent posts usual refer to how busy he is while simultaneously telling fans they just need to be patient.
It's been 11 years since the last book in the main ASoIaF story line. _26 years_ after reading "A Game of Thrones" I'm not even mad. I've just given up. I'll just put this in the same category as Gordon R. Dickson's Dorsai saga or Coleridge's Kubla Khan: brilliant but never-to-be-finished.