The GoT show runners appear to have totally misunderstood that, and threw the suspense and world building stuff under the bus for creating moments of interpersonal drama. But the drama and actions increasingly made no sense vs the buildup of the previous seasons.
Who are the white walkers? What is the rest of their history? What are their goals? This was the big driving mystery of the show, and they simply decided to wrap it up in a single big battle with no further revelations.
That totally removed the payoff a lot of people were waiting for. Much like Lost, it became clear there's no actual coherent mystery.
Maybe GRRM deserves some criticism for not having things wrapped up himself. But mostly I think the show runners just totally misunderstood what was driving the earlier seasons.