NTR is unorthodox. Even if you don't self-insert, it's the same as not liking futa or judging someone for liking feet. Porn media is porn media, and NTR is a turn-off to some people including myself. It's like Metamorphosis or 177013 where you genuinely can't jerk off to it because you feel bad for the MC. Just jerk off to hot chicks man, why does anyone feel the need to add human suffering as a topping to porn?
It's the same for SAO as you mentioned, why would anyone want to see the MC get cucked? Let me tell you: jealousy. Those that like NTR are either cucks or jealous people who lead trashy lives: i.e. they want to see someone get cucked because that someone has things THEY PERSONALLY don't have.
Any normal person would just shrug. It's the same thing as normal people not wanting female characters to get raped for just being a bitch. Liking NTR is something deeper, something related to the personal lives of those who enjoy it. Hence why normal people don't really like it: people who like NTR are, well, often messed up in the head.
Eh, I'll have to disagree with you here, because there are a
lot of potential reasons to like NTR as a fetish. Some people do indeed get off on someone's life getting destroyed, meaning the cuck. Those are usually the peeps into Netori. Some people get off to the idea of being cucked themselves, the people that self-insert as the cuck. Some people just jack off to anything as long as the art is hot. Some people actually like to imagine themselves as the person being stolen, about being desired so much that someone would literally steal them away in a storm of lust. Some people don't care about the NTR specifically, and are into it for the sluttification and/or corruption of the person that's being stollen.
I'm in the last category myself. I like corruption as a fetish. The idea that someone becomes an
objectively horrible person due to lust that's as strong as literal hard-drugs. It's hot. Unfortunately, sexualized corruption in a lot of Hentai media is just slutification, and NTR is one of those genres that genuinely turns things into corruption, because the person being stolen genuinely becomes a horrible person in some objective way by the end. (By that same token, it's why I'm not fond of BSS, because those almost never have corruption and the stealing is often in the cuck's mind more than anything else...)
BUT!!!!
It's only hot if it's fiction. If it's anime tiddies and all that jazz. I don't even want to
imagine 90% of the fetishes I'm into in reality. At all. Under any shape or circumstances. I can't even watch porn with real people. I just can't get off to the stuff. Objectifying real people in any way is just not ok for me.
Plus, it's not like my favorite fetishes, that is to say, tentacles and babes in ridiculously skin-tight bodysuits, are even
possible in reality...
Does that mean I'm messed up in the head? Uh... Why? I've never harmed or hurt anyone. No one IS getting hurt. At all. Not even me. I don't
have to feel bad about pixels and whatnot. No one does. It's a choice.
Ted Bundy got off on torture, rape and murder, didn't he? Is it kinkshaming if I call him a terrible monster for it? Kinks are okay so long as they don't harm those around them. Everything is okay under CONSENSUAL CIRCUMSTANCES. Willingly transmitting STDs to people isn't okay, dude. Everyone's saying "oh no don't kinkshame" until they themselves get an STD because some sick fuck got off on it. For that specific example I'd argue it's no longer kinkshaming and just enforcing human fucking rights. Other than that, do whatever you want with bugs, man.
See, if we'd be talking about something in reality, then, yeah, the concept of kink-shaming doesn't apply. One's personal freedom stops at the point where they start bringing any kind of physical or emotional harm to another, etc etc. Bug chasing and the like is definitely disgusting IRL, and I didn't even believe it was a thing IRL until I saw vids of people licking toilets to catch COVID... >.>"
If we're talking about pure fiction though....
Why care? Anything can and should be permitted, with the only limitations being restricting hard media from underage members of society as well as the mentally ill, as those individuals may not be prepared to properly process such things. Aside from that... Why should anyone care what someone gets off too?
If we're talking about fictional media and someone's enjoyment of fictional media, kink-shaming is always a thing, and the moral high-ground doesn't exist.