In an interview with Observer (via The Guardian), Game of Thrones author George RR Martin described the end of the show as “freeing,” and insisted that the controversy over the show’s ending, which many critics deemed lackluster, wouldn’t impact how he tackled writing the Winds of Winter and other A Song of Ice and Fire books.
“It doesn’t change anything at all … You can’t please everybody, so you’ve got to please yourself,” Martin told Observer.
Game of Thrones’ eighth season was criticized for both its unusually short length, and for how that quickened pace seemingly fumbled up character motivations that had been boiling for the prior seven seasons. Ironically, while the show was blitzing through character arcs and plot threads, GRRM says it was a key source of why he’s been taking so long to finish Winds of Winter, the next installment in his book series that sparked the show.
Source: IGN.com GRRM Says GoT Ending Reactions Won't Change Winds of Winter