I'm sorry, you playing the game is effectively cucking other guys's girls, that's Netori which falls into NTR as well.
Don't kinks shame.
Also, NTR is optional and can be disable. More options is always welcome and can help making the world more diverse and lively.
More often than not, even if you're a vanilla guy, you can thank NTR aspects of a well-made game to make you care about heroines and pledge to protect them from harms and others, it is a drive and an optional objective for you while playing the game, it is there to breath a sense of impending cuckolding into you so you know you have to act, sooner than later. There's no good NTR without true love after all, but that's still too deep for you for now.
You don't always play the dumbed down PG 12+ version of an adult game do you ?