Probably the reason why the forum present itself as a place where you'll find "adult games", and not "porn games".
Yet there's games where it's legit to complain about the sex content, like there's action movies where it's legit to complain about the violence. Not because of its present by itself, but because the way it's inserted in the story.
Imagine an action movie where the Hero punch everyone he met. He enter a bar to take a beer, he start a fight. He exit the bar to go back home, he cross some punks that he'll punch. He enter his building, he cross his drunk neighbor and punch him... And this is just the first two minutes of the movie.
This wouldn't be a movie, just a ridiculous pretext to picture a guy who punch people. And there's adult games that are like this, having a potentially interesting story but also sex behind every corner, totally unjustified and that come out of nowhere.
The Guardian (now rule7 banned) was like that. Not that the story was really interesting, but the MC couldn't see a girl without fucking her. One time he was in hurry to save the life of this sister, goes to say it to two girls, fucked each of them, and don't even said that he was leaving to save his sister's life. It was really ridiculous and, when the game was still available, many reviews contained something along the line of "the sex is so annoyingly invading the story that I skip it most of the time".
Not that you can't have purely fappable games, but the cost of game making is lower than the cost of movie making, so be a bit more creative and don't put sex for the sole purpose to put sex.