Let's see.
First of all, "our culture" needs to be defined, I assume you mean your own, so you might specify.
Games are produced for and played by an international crowd.
Where I come from and live, in a European country, the female breast is not banned as a shameful part. At least not in the way that for example breastfeeding a baby in a public place or taking off one's shirt at the beach would make someone call the police. Yes, it's unfair that when it's hot in summer my brother can walk across the street in pants only and I would cause a scene if I did, but seeing a shirtless woman (and yes, also showing the "areola") can still happen in advertisement or a movie rated 12+. And at a public sauna in the specific rooms or huts with the high temperature people will be naked (yes, men and women) without it having any sexual context. They're just sitting there undressed instead of being dressed, because wearing clothes at 100°C is unhealthy, and that's it. And if I decided to be shirtless in my backyard and my neighbour would stare, he would be the rude one, not me.
So a naked female breast won't give a 16+ or 18+ rating in my culture and therefore is hardly considered shameful or pornographic.
Now, murder.
Unlawful, premeditated killing of another person without justification and with malicious aforethought.
So unless you're talking about a specific game or specific situation, I don't think I committed murder in any game, except for, well, Assassin's Creed: Odyssey, for obvious reasons. And even there I'd argue about the "malicious" part.
Yes, we kill in RPGs, but usually in self-defense, or for some other reason, or in a context where only a paladin would call it murder. Most games I have played don't have inevitable situations that require you to murder someone in cold blood, especially not an innocent.
So as I said, the situation and circumstances need to be specified a bit. It was probably just a "My place rates even moderate nudity worse than violent crime" rant by the OP. That's fine too I guess, but as I said, some context about which situation, which game, which culture would help, which is why I decided to share my perspective.