Im all for it, a couple of games tried this premise and later abandoned it, much to the dismay of many...
That said focus on your vision, it might not attract a large following, but if you try to satisfy a bunch of people, you'll end up ticking off several groups at once...
For example if you promise a vanilla romance story with plenty of incest lesbian sex, and deliver nice steamy content for the first two versions, but then "whinners" come into your thread asking for "drama" to make the story interesting... and you cave in adding an ugly black dude to fuck one of the sisters and corrupt her a little, I would never look back at your game... I know plenty of others wouldnt either... the "cuck" crowd and the "lesbian" crowd dont mesh well together... you'd be trading one minority fetish group for another, and incest wouldnt be enough to keep both sets of groups satisfied...