Well, I do have poll results that clearly show that a much higher percentage of the general player base self inserts than NTR fans.
https://f95zone.to/threads/poll-do-...ay-games-with-a-third-person-mentality.89596/
https://f95zone.to/threads/poll-ntr-fans-self-insert-roleplay-or-third-person.86527/
If you don't self insert, you are not gonna have a lot of emotional attachment, catharsis, or anything of the sort. It's simply just dark porn, where the situations are immoral and the elements of female corruption are high. Granted, you could still empathize and feel bad for the guy without self inserting, but these types of players still enjoy NTR (at least those that are choosing to play NTR games), though I find that they tend to prefer stories where the cucked guy comes out at least OK at the end, if not outright winning in some revenge ending. They also probably enjoy netorase more than standard NTR stuff.
If you do self insert, it's obviously gonna bring out strong emotional responses. A small percentage of NTR fans do thrive on those bad feelings by self inserting as the cucked MC. They enjoy that. And obviously, the overwhelming majority of anti-NTR players who self insert will blow a fuse when stuff like that happens to "them."
Obviously, self inserting NTR haters and non-self insert NTR enjoyers don't make up the whole player base. There are non-self inserters that just don't like fucked up stories, and the true cuck players that self insert in NTR. But clearly, at least in the NTR fandom, self inserting is the minority by a pretty big margin. It just makes sense intuitively too. Does it make more sense for people to enjoy increasingly fucked up porn stories as they get desensitized to vanilla over the years? Or do you think that the number of masochistic cuckold people in the world is high enough to explain the amount of NTR content produced and consumed? I'm thinking the former.
And before we get too sidetracked, Desert Stalker isn't really NTR or even netorase. It's just "alpha sharing" that is completely power fantasy instead of being thematically derived from cuckoldry or masochistic tendencies like in the typical netorase stories. And before someone loses it again, no, I'm not saying sharing is more alpha than not sharing in this game. It's just two ways to play the same character. MC is completely in control in both routes.