NTR is a deeply visceral fetish in the responses it can garner. It is more in line with Necrophilia, Rape, Sissification, or Bestiality than say anal, a harem, or even incest. Some things are not *just* a fetish, they can trigger real responses when seen even in media. This is true in movies and other media as well. To add to the issue with NTR as a type of content is that it is also the only one people get called names for *not* liking. I've never seen any kink shaming like that from pro-NTR fans shaming people who dislike NTR. A Rape victim might have a huge problem seeing a rape scene in a movie like The Accused. Would that rape victim be insulted? No, people would say, "Oh, I didn't think about that, sorry, this media isn't for you then."
No one gets called, weak, a closet cuck, pathetic, or accused of being "(bat shit insane) about their fake adult game waifus," (to quote someone above me), when they say they'd rather not see a love interest in a game get murdered and her corpse raped, have someone shit on her face and force her to eat it, or see her get fucked randomly by a dog. But say. "I'd rather not see a character in this game get dicked down by some other guy," and the names start flying. Hell, even just ask, "This game got NTR, or NTR avoidable," and you get insulted and called an Anit-NTR brigade, and worse. Which just makes the people who were critical (often just asking about it and not even critical) fire back as well. The pattern plays out all the time, but it usally gets nuked so you might not always see it after the fact.
Game has or adds NTR - some player, "Is this avoidable," "Why did this get added all the sudden, I think that was a mistake," "It was dumb for the developer to add this." (Often just one player asking if NTR is avoidable can be enough to spark it)- Pro-NTR crowd, "Here comes the brigade," "Bunch of kids taking their games too seriously," "Grow up and get the fuck out." - Anti-NTR crowd, "Fuck off, they shouldn't have added this," "It was a vanilla game before and that's what we were promised," "You may be a cuck but I'm not." - back and forth for a while - then thread gets cleared and we repeat it over and over.
Even with something as common (and money making) as Incest, I would say it should *never* be added in the middle of a game that didn't have it before or at least wasn't foreshadowing it. NTR is the only fetish I have ever seen get randomly dropped into a game out of nowhere and then people who are upset or even just confused why it was added get insulted. The whole point of NTR is that it evokes negative emotions (jealousy, fear, and powerlessness), just like Rape (fear and powerlessness), Some Heavy Domination (powerlessness and humiliation), Sissification (humiliation and degradation), Bestiality (humiliation and degradation), and Necrophilia (fear and disgust) and some other fetishes. And NTR should be considered as such and treated like those when it comes to being honest and upfront about its existence in and addition to any media. To the people who like these fetishes, they transfer those negative emotions into a sexual response, which is fine. There is nothing wrong with that being done in the safe confines of a virtual world. The problem is that they fail to see that others, in fact many others, might not do that and might just want to avoid those negative emotions and focus on positive ones.
Many NTR fans get off more from one scene of NTR in an otherwise standard game because it isn't the scene in the game they like, it is the response. They get off on how they know that one moment just ruined the game for so many others. This is why one whale will offer a lot of money to get a developer to add one scene and then bounce. He doesn't give a shit about the scene or the game and would likely never support a full NTR game (evidence by the fact that those game are few and far between and rarely get off the ground) but he will get a lot of pleasure from knowing that he caused such a shit storm for so many others.
But that's my two-cents. I hope you all have a lovely day.