I think perhaps you shouldn't speak with such authority on the medium. Many have terrible writing, many have excellent writing. It depends on the author(s) and also to an extent on the localization team if it's being read in English or another language.
What "authority"? I'm giving my opinion; this started with the comment "I'm not a fan of the genre". I don't claim to be an authority.
All of the visual novels I've played were terrible and their plots would have been rightfully mocked had they been books. They also had little to no branching and lacked any meaningful decisions. Note I played many that were highly regarded in websites such as Home of the Underdogs, whose owner was a fan of the genre.
That's just my experience (based on playing games since the Commodore 64). I base my opinions on my experience. I don't push them on you. It entitles me to say I'm no fan of the genre -- no more, no less.
Sorry if this upsets you.
I wonder why a struck such a nerve for multiple users here on HN just because I said I wasn't a fan of a genre. I didn't expect a kind of Spanish Inquisition!
Well, the problem in this case is that the answer isn't "lots of them" but "very few of them". And those that have options, based on reviews I've seen, are mostly cosmetic, the story is "on rails".
Being "on rails" defines the genre, I'd say. That, and terrible writing.