Well, I think it's a much larger problem in this sort of games. I, as much as the next guy, am for a good story, even in this kind of porn games. The problem is, most of the Devs aren't good writers but they think that making the story overdramatic and overcomplicated will do it good.I'm not sure if I'm alone in feeling this way but the "story" is extremely unappealing. I don't give a single fuck about some harebrained collusion plot or whatever you want to call it. It's obviously meant to try and be "intense" or "dramatic" or whatever but it's just a fucking snorefest. I just literally could not possibly care less about the "mystery" behind it all. None of that feels the least bit important.
The game series was a thousand times more appealing when it was simply about Sara and meeting other girls and how they interacted. All of that was more than enough, there's no reason to add all of this irrelevant junk in an attempt to "spice up" something that doesn't need it at all. Because it doesn't add spice, it just dilutes the stuff that is actually interesting with a bunch of useless white noise.
So, since we are here for sex anyway, I completely agree with you. The simpler the story, the better. Especially when it comes to incest, harem, corruption. We don't need a lot of drama in this genre, just keep it within the family