Are there any people who play visual novels for the story and regard the sexual content as just a bonus?
I'd say you want people who aren't horny teenagers and look for depth in their porn games.
Shouldn't be too hard to find this type of audience even here on F95 if you offer quality work.
That said, porn is also important because you're making a
porn game.
Ideally you'd want to fuse porn with non-porn so that all of it flows seamlessly.
But take heed, you will fail horribly if porn ends up being the only good thing in your game, or if your
game ends up being the only good thing in your
porn game. You need to balance this shit well and not neglect either side of the coin.