Old post, but in case anyone is still following this thread or happens across it I have a couple of questions and points in regards to ntr.
A lot of the sentiment from ntr lovers seem to focus on the ideas of corruption and the gap between ntr and vanilla.
In regards to corruption, I admit that ntr does this well but the concept of corruption doesn't require ntr fundamentally. I have read a lot of hentai mangas that start with a stubborn ojou sam or a tomboy which then transformed into sluts in vanilla style (where they basically wana fuck the shit out of their lovers) or even traditional whore style, becoming cum dumpsters and fucking anything alive. The whole aspect of corruption does not entail ntr.
In regards ntr as a whole, I don't think the actions themselves are too discussing to the general hentai viewer, but the perspective is what really matters. In ntr we are generally seeing things from the perspective of the people who get hurt by ntr, which is the main source of disgust with ntr I think. I mean there are a lot of hentai with corruption themes and even rape themes that are not ntr. Most people focused on aspects of ntr that are not exclusive to ntr. The main aspects of ntr is the feeling of sadness, loss, anger, and extreme jealousy and madness. You, as the person empathising with the MC, see your beloved taken away from you, being used and maybe ending up enjoying another man. Maybe I'm an extremely empathetic person but I feel extreme sadness, jealousy and anger when I see this happens.
Maou no Hajimekata is an extremely interesting manga that explores the other side of ntr. It is not really a hentai manta since it doesn't focus around sex but there are elements of it. You can see in this manga characters being ntred but since it is being done by the MC you don't feel the same as when reading a normal ntr. People who don't like rape at all might not like either perspective of ntr, but others surely will.
In summary the whole hatred towards ntr stems from the fact that the we see tge story from the perspective of the loser. It is like if you had a game like GTA but instead of being the MC who gets to do crazy shit, you are a passerby who gets killed instantly so that the MC can get 10$, or you are the elderly driver that gets pulled of a car that the MC stole. If you rewrite all the ntr stories from the perspective of the winner then people wouldn't be pissed off. People generally don't hate evil MC (look at Death Note), but they hate to be the sissy bitch jerking off outside the door of a room as his lover is getting fucked by two studs.
That is my two cents on the topic.
