It's just the typical prudish nature of society as a whole. Where nudity gets 18+ ratings while violence and gore are okay in 12+ rated media...
Sprinkle in the fact that BG3 isn't any more violent than a majority of games, while it features more nudity than most games and you get a thread discussing the sexualized nature of the game rather than its violence.
The more I think about it, the more I'm convinced that this is a terribly myopic position.
The position itself is so convinced it's right that it avoids any intellectual rigor in understanding why there's a cultural difference between the presentation of sex versus violence.
