Too much?
It happened again.
I was enjoying a story and then the ending just…well, ‘disappointing’ might be the kindest description.*
It wasn’t that it was sad. I’m not a huge fan of stories mired in misery, but a tragic ending that fits the story is a great one. Some of the best things I’ve read have ended in tragedy. And, importantly, tragedy that I didn’t see coming during the story. But when it happened, it fit. It might have broken the tangle of baling wire and coyote teeth I call a heart, but at least it was broken for a reason.
This, however, was tragedy without purpose. It didn’t fit the story; in fact, one part was at best a cheap ploy to illicit FEELS, and at worst a betrayal of the characters.
So. Yeah. Not a fan.
I know not everyone feels this way, but here’s how it is for me: an unsatisfactory ending–either happy or sad–ruins an otherwise good story. You can create the best thing in the world, but if you fail to keep whatever promises you made in the course of it, then we’re going to have a problem.
It’s not about twist endings, either, because some of those have been my favourites. But, again, it has to be a twist that serves the story. Not one that’s an author’s attempt to shock just because.
As with all my advice, your mileage may vary. For you, endings might be less important than the journey it took to get there. I understand that, and the story that ended so poorly recently had many great parts leading up to that shit show. That might be enough for you.
But if I was going to offer advice to writers, it would be this: keep your promises, or don’t make them in the first place. Because an unsatisfactory ending is a betrayal of the audience’s faith, and a betrayed audience stops reading your stuff.
Stick the landing or don’t bother to show up.
*The unkindest was probably heard by all my neighbours. Screw that, they probably heard it on the ISS.
Bare Knuckle Writer 
I absolutely agree with this. Extended to TV as well. I have had several disturbing experiences with shows that I invested YEARS in. Then they pull something out in the last episode that cheapens the entire series. It is a horrible feeling to have invested that much time in an experience only to be cheated at the end.
(No spoilers, but “Battlestar Galactica” and “Lost” come quickly to mind).
Let’s not speak of Lost. It makes my blood pressure rise.
It’s the whole Chekov’s gun principle. We were just talking about this in my writers group this past Sunday in relation to a story that made a promise & didn’t keep it. It’s always disappointing.
Agree with all the above. Apart from the quality of the writing, the worst thing about the last Twilight saga book was the ending. She set up the Volturi (old vampires for those not having delved) as the big bad throughout the series, but then they *spoiler alert* growled a bit on top of a hill and walked away. How did her editor/agent not say anything? Is it because by that point Twilight was just a way to print money!?
A bad ending is the last thing you give your reader and it stays with them, longer than anything else. It’s like a limp handshake at the end of a job interview – best avoided.