These statements appear to be contradictary. In your first post you say you implied that you had read only a small piece of writing standing in the bookshop. The latter implies that you had read the entire sequence and was able to assess the book's literary themes and impact in a meangingful manner.I would suggest that that he does not meaningfully engage with our cultural moment in a fresh and vivid way, nor does he re-engage our past. This does not mean that SFF cannot do such things, but only the work of George R R Martin fails on such an account.
If we examine A Song of Ice and Fire in greater detail, it is noted that the book does indeed engage with our cultural moment (topics such as terrorism and the ineptitude of politics to deal with economic and cultural crises are prevalent) and also re-engages with the past (the entire series is a re-appraisal of the romantic, chivalric legends and their exposure as exaggerations, if not outright lies). The series fundamentally concerns itself with the morality of power and those who want it, or have it thrust upon them, or desire it but have no aptitude for it. This also ties in with notions of responsibility, consequence and expediency.
A questionable use of the word 'fact'. Facts traditionally can withstand repeated challenges and be proven beyond any reasonable doubt at any time. Unless you have mastered the art of time travel, I would submit that your 'fact' is very much 'an opinion'. An opinion which interestingly is strongly reminiscent of those expressed about (at the very least) Charles Dickens and J.R.R. Tolkien by their contemporaries. I recall the critic in the early 1960s who smugly proclaimed satisfaction that The Lord of the Rings never achieved much and now languished in obscurity, shortly before he was proven spectacularly wrong.But the fact remains that in a hundred years, someone who mentions the author or his works will be greeted by "Huh? Who? What?"