>Why GRRM chose to almost normalize it is strange.<
The entire plot of the books and video revolves around the fact that the evil family steals the throne since the new “king” is the spawn of the queen and her twin brother, not the son of the murdered King. They put a 2nd false son on the throne, when the 1st one is poisoned.
I cannot see by any stretch, that the George RR Martin frames that behavior as mundane.
Yes do I see your point. Maybe with all the other sex and nudity in the series, there’s just a cumulative effect. It’s all just too much.