Ok, first, when have I EVER praised the writing in this game? I'm serious, when have I because I don't remember doing so. About the only route I thought had at least passable, fantasy fulfilling writing was the Olivia route, and MAYBE parts of the Lisa GF route early on. But that's it.
As for the Eric route, fucking HORSESHIT! You had an image of Eric jerking off to Alice. Mom didn't care. Ok, fine but NO ONE in the house save Kira even had an issue with him either. Was there ever an option to tell Alice that he was peeping on her and jerking off? Hell, talking a picutre of him fucking her actuall should have been an option logically, because it happens, but yeah that great writing.
And yeah real world ic is usually fucked up beyond belief. If DS wanted to tell that type of story, he could have. Hell ICSTOR's Incest Story is also horribly written, but at least it goes for what you were talking about, using blackmail to essentially rape his whole damn family until they like it, because yeah, that happens. But it's a) clearly a fucked up fantasy land and b) it knows what it is, (the sequel went for romance though, which was fucking odd).
BB at one point may have known what it was. But it sure as fuck doesn't right now. The game is a lesson in tonal whiplash:
Get used to being the pervy, sneaky brother who is wearing down defenses?
JUST KIDDING ERIC IS HERE TO FUCK UP YOUR LIFE!
Get used to the game being some sort of NTRish thing where you're fighting off an asshole for control of your family? Well he's gone now. Thank Christ. (Unless you love NTR, then you'll bitch forever)
Happy that Eric is gone, and you can actually DO SHIT again?
Don't get too happy, because every choice you make is dictated by Kira aka Sexy Eric.
Do you like slowly introducing Lisa to sex as you seduce her while she asks for romance?
Nope she's a submissive who wants to watch you fuck other girls and cares not a whit for the romance she said she wanted.
Slowly winning Alice over to your side after helping her start her blog, giving her cash, and fucking her and her girlfriend, sometimes on camera?
TOO BAD SHE'S A DOM NOW, fucks around on her girlfriend behind her back, and bonus, she now runs your sex life with Lisa.
Make peace with the new status quo?
Prepare for a whiplash cycle, she seems kind and loving half the time, until she turns into a total cunt.
BB doesn't need to be much, I mean let's be honest here, it's a story about a pervy asshole who wants to fuck his pervy family. Not much of a story there. But it does need to be consistent within itself. Right now it's failing at the basic consistency needed for a porn game. And that's fucking saying something,