Again, different things for different people. But there are actually a LOT of games out there that are just ordinary sex, darker stuff is actually pretty rare, especially in western games. If I'm understanding you right you're basically saying "why can't this be a game where the hero can just enjoy having sex without the dark overtones?", but those overtones are the whole point. That's the kink. The drive of these games has always been to have that darker flavor, they're very much games where the bad end is the good end, ie what you as the player are actually trying to achieve. They're about sadism and masochism, though more mental than physical, and obviously not as brutal as that might imply. But if that's not your flavor, that's entirely fair.