My best guess, if we want to buy into this argument and want to find a psychological reason...
aside from personal traumatic experiences which really aren't as common as porn movies would want us believe (the majority of cheaters aren't actually caught balls deep in their lovers when they are caught) is that it's simple insecurity, which is a perfectly fine sentiment to have.
Almost anybody is insecure about at least something in their lives... it doesn't help that there are a lot of cultural stigma attached to this particular brand of insecurity and that in recent years people have started to try and compartimentalise behaviours and "types of reactions" assigning it every letter of the Greek alphabet without there being any actual scientific or factual logic to those definitions.
Way too many countries still have this situation where men are brought up to have a stiff upper lip, to not show emotions, to suck it up and deal with it, and that doing anything different is somehow less than manly and thus automatically gay or defining you as a lesser man/person.
A lot of people with deep rooted insecurities buy into those arguments as a way to externalise the issues they deal with and potentially blame something or someone else... so if you feel unattractive, if you're not scoring a girl, if you're simply too young to know better, if you've had bad luck with your relationships or sex life, if you have body image issues or whatever other impediment... A scene where your character is, in your eyes, victimised, breeds insecurity and to defend yourself from it you lash out at anything that might make you feel less than a top dog macho man, because that's what the society you live in tells you you should be.
To me it's a lot of bull... it's perfectly fine to deal with insecurities, it's perfectly fine to have a human reaction to being exposed to them, it's perfectly fine to indulge in a fantasy that doesn't show you as the ubermale, or that in some marginal way exposes an insecurity. Ultimately games are a safe space because it's just you and your computer/phone... and if you feel angry about a thing, or sad, it may become a positive drive for change.
Note I said it's a reason, not a justification... if you take your issues, your traumas or just your simple insecurities and weaponise them to be mean to people you don't know over the internet, people who might deal with similar or worse situations, that's still an active choice you make, an actual investment of your time spent to spreading your crap on the net, and you need to grow up, find a different outlet for your frustrations (maybe counseling?) or just stop being a dick.
In the context of this forum, that would mean maybe not going out of your way to antagonise people because they have different tastes, tastes that confront you with something you don't like. It's doing you nor anybody else any good..
And if you notice that even the remote possibility of NTR content triggers a strong emotional response in you, to the point that you lash out at people... then maybe you need to either count to ten and see if it's worth it, or take a step back from seeking refuge in playing these games and sort your shit out, talk to someone about it.
still rambling
