I think that's exactly it, if you are self inserting yourself into the game, you probably don't want to be cucked or made to feel like a loser.
Well, it's depends. The sadomasochistic component is quite thrilling. Especially if you're projecting both the MC and the main girl onto yourself. On the other hand, finding a good ntr game where you can self insert is almost impossible. In most ntr games the characters are poorly written, don't evoke any emotion or interest at all. And the game only holds up on the ntr concept itself. So yea, most of the time I just feel like a silent spectator.
To anyone who likes NTR but doesn't like the more gangbang-y style of NTR: do find yourself enjoying netori games or stories almost as much as netorare? That part of what you get out of the game is by investing a bit of yourself in characters like Zeno or Ulrod?
Not as much, but I can enjoy it. But only if the main character isn't completely douche or/and Marty Sue . For example, Mars from "Hero Party Must Fall" is a good netori protagonist. I can definitely empathize with him and play as him. He is capable of deep feelings, is somewhat hostage to circumstances, has a credible motivation, an outlook on things that changes over the course of the story.
But If the main character is the kind of edgelord who steals other people's women just because "OO HE'S BIG BLACK ALFA BULLY AND LORD OF SHADOW" then it's trash and the people who self inserts into this type of character are trash too.
But even if netori are good, it gives you a very different feeling and a very different perspective from netorare. Closer to vanilla and not as searingly excited as netorare.
Also, It's very easy to lose the sense of importance of the relationship (and its destruction) when none of its participants are the protagonist.
So in my opinion, netori is weaker than netorare. It doesn't explore the cheating theme enough, the corruption feels much weaker, because there is no jealousy and sense of loss, sense of wrongness of what's happening, the sense of dirtiness, of forbiddenness. There's also no voyeurism and many other very interesting perverted things in netori.
Sadly, In most cases, netori feels like it doesn't know what it wants to be. But of course, there are exceptions.