I understand what you're saying. It's good that a game can please most players.
But why would someone play an NTR game to avoid NTR?
To me, it doesn't make sense to play an NTR, since that's exactly what the game is about, just to avoid it. If you prefer vanilla games, then stay away from NTR, unless the game has a vanilla route with unlockable sex scenes, which is rare in games with that kind of proposal.
That's exactly why.
When it happens, you have knowledge that you (as in literally you, the player, with actual input rather than the character) could have prevented it and been on the happy vanilla route. But you didn't. It's the best kind of spice. Or that caution when you go in blind not knowing if your choice/gameplay is going to send you down one route instead of the other.
It's also a narrative flex on the author's part. Now you have
two distinct stories / genres instead of just one, which broadens the appeal. Or hell, even three since there's a number of games where you can still save a partially corrupted heroine.
As for
Scars of Summer specifically, it's extremely annoying because it has the framework and character building of a vanilla story (Ryoka at least, Saki's already too far gone right off the bat). Right. Freaking. There. MC should've been able to confess and bang after collecting the childhood memories, with more lewd events sprinkled around the map for days of the week before the final big romantic event right at the end rather than the relatively empty limbo of the true end route. An actual fleshed out route and set of events with a start flag much like the NTR ones. But the creator goes out of their way to not give a crumb of coochie to Keita and what he ended up getting in
After was offscreen (which is still an exponential improvement over the base game at the very least).
For what the game did well, it also felt like a massive wasted opportunity and the lack of content in the true end route is one of the most common complaints I've seen and personally had of the game (and yes - I did like the corruption stuff). Most other games that have little to no vanilla content give you a quick good end near the start if even that - SoS turns this into a potentially multi-hour tease with zero pay off.
War Shop's
NTR Knight has it beat on this frontier because both concepts are literally married to the gameplay loop and narrative. Play well and block attempts, get a bunch of vanilla sex and vanilla outcome. Fail to block some attempts, get to be a voyeur to more foreplay-ish acts but still get the good end. Fail to block a decent number of attemps, get a good-ish ending with adultery included. Fail to block many attempts, full on NTR end.
Sorry for the many words, but my ire over this particular aspect of SoS was reignited after four years lol