They have still volumes and arcs with plots that have climaxes and conclusions.
But Visual Novels that are story focused tend to focus on just one big arc.
You forgot the effective difference, the one that make it impossible to compare a story based VN with a TV series: all the behind the scene.
Firstly, and with still few exception, a TV series is wrote by a bunch of scenarists, each one taking the lead on the story or arc he came with. This while the guys behind the cameras, lighting, sound recording and post processing, plus the director, aren't always the same persons. Therefore, you can't fully judge it on a single episode ; it can either be the best one of the season, or at the opposite the worse one.
Seeing the first episode of
Vinyl, by example, can't tell you much about the quality of the picture, simply because not anyone is Martin Scorcese and, whatever how hard they'll try to do like him, it will just be a try. This episode is apart and, while the other aren't necessarily bad because they aren't directed by Scorcese, they'll still not be as good.
Then at the opposite you've Visual Novels, where the story is wrote from start to stop by the same person, and the visual also done by the same person. This confer them a continuity that is absent from TV series.
There's obviously some fluctuations, rare are the people who can give 100% all the time, but they are just small variations ; the author could have been better in this part, or surpassed himself in that one, that's all. Therefore, seeing just one release is enough to tell you a lot about the quality you can expect from the game.
If it were Episodic like I said before I have no problem with, if they can Satisfy with each Update that would be ideal.
But how many arcs have been concluded?
How many projects have even one arc concluded?
And so ? The quality come from the conclusion ? Then
Lost, or
Game of Thrones, (it depend of your own taste) are total piece of shit, right ? Bad quality series because their conclusion feel ridiculous to your own eyes...
No, what is ridiculous is to think that what you're judging at that moment, what you're talking about, is the quality. Both series are of good, when not high, quality, but they aren't really appreciated because of what part of the public see as being a really lame conclusion.
But it don't change the quality of the series, not even the quality of their last episode. The actors are as great in this episode that they were in all the other ones. The writing is as good, the picture, the sound recording, the FX, everything is of great quality, it's just the story of this episode that is lame. But the story don't do the quality, it just do the appreciation.
The best writer can still write the worst story ever. The style will still be the same, the quality will still be amazing, but the story will be nothing more than a piece of shit. Quality 100/100, appreciation 0/100.
The reason why not everyone can be a critic is precisely this difference between quality and appreciation. To be a critic, you need to be able to admit that the book/movie/whatever have qualities, even if you totally disliked it. You need to be able to say things like "the picture in this movie is one of the best I have had the occasion to see. The camera angle is always right, trying to project all the actors' emotion right in our own memory... too bad that the said actors are less expressive than a dead fish and have nothing to project excepted annoyance."
Quality isn't really a personal judgment. Anyone that take the time to effectively look at it can see the quality of a scene. You've the character that try to express a feeling, repeating the same thing in many different way, while the CGs, through the gesture, the expression of this character, show you a different feeling. You're facing the internal conflict of this character, the opposition between her desire and what is "the good thing to do". You're hearing (well reading in fact) her not trying to convince you, but trying to convince herself.
Whatever what yourself think about the situation. Whatever if, from your point of view, the conflict have no reason to exist. The quality isn't in the story, it's in the realization. Static images and wrote words achieve to express this opposition, to make it obvious for anyone who take the time to effectively look at what is in face of him. You're deprived of the tone, you're deprived of the effective hesitation in the movement, what are two major elements of understanding in real life, yet you feel it. It's quality work, dot.
And you don't need to have the full story, to have a completed story arc, to see that it's quality work. You don't wait the end of the game, the end of the arc, to suddenly realize that, five hours ago, "this scene" was really great. Players haven't waited the end of "My name is Luna", to be hit right on their empathy. They don't need to see the end of the game to feel sad, and it's not only for Luna that they feel sad, it's not were the emotional charge is.
I repeat myself, I know it, but if you need to see the end in order to judge the quality of something, then you don't talk about qualities, but about your personal appreciation. And it's something totally different that is totally unrelated with the effective quality.
I do not judge projects by what they are not trying to be, I judge things by what they are trying to be and fail at it.
Quality isn't a judgment, it's an observation. You see it, you don't judge it.
Quality don't lead to thoughts like, "I past a good moment", but to thoughts like, "I'm passing an amazing moment right now". It's something you feel when facing it, not that you notice once it's passed. Quality is what make you stop reading a book, lost in your thoughts, lost in the pleasure you just take reading this part. It was so great, that you need to catch your breath. You've been stunned and have to recover. It's what quality do, and it's obviously something that happen far before the end.
This while appreciation is was let you sad because you reach the end. You appreciated it, therefore you want it to continue. But this can come from something of bad quality, it's not the oeuvre that you want to continue, it's the story. You don't have this sadness at the end of a quality book, unless the story itself carry it, because you know that now you'll be able to read the next book from this author ; now you'll go for another amazement. The end of the book is not the end of your journey in quality, it's the step that open the next part of this journey.