The late film critic Roger Ebert once criticized a movie by pointing out that the premise (Kate Jackson discovers her husband is gay and tries to deal) was pretty much the entire plot. He did not consider that a good thing.
Reading SPAWN OF MARS and Other Stories, a collection of Wallace Wood’s EC Comics science fiction art (cover by Wood, all rights to current holder) I’m inclined to think it’s not a good thing if telling the ending twist tells the entire story. For example:
The Probers. Scientist who thinks nothing of vivisecting animals winds up in the clutches of aliens who think nothing of vivisecting pink hairless apes
The Sinking of the Titanic. Man goes back in time to prevent the sinking and causes it instead.
Breakdown. Woman warns the authorities that aliens are hiding among us, plotting to take over. OMG, the authorities are aliens themselves! (as I mentioned here, this is a very old shtick in SF).
And so on.
It’s not like twists or last minute surprises are a bad thing in a story. And it’s normal to structure a story (at least on the later drafts) so it leads towards the end you have in mind. But there are some stories, like these, where it’s all about the ending. The rest of the story is just a set-up as necessary yet unimportant as the set-up in a joke.
These stories usually don’t work for me (there are exceptions). I’m not sure they work for anyone, because I don’t run into them except in old anthologies. Sometimes I can sense it on the first page or two, the feeling that whatever’s happening on the page is just marking time until the big reveal.
That feeling is one of the reasons they don’t work. Another, as Orson Scott Card once said, is that setting up the end often requires distorting normal behavior and characterization. To avoid letting readers see what the big revelation is, the writer can’t have the wrong questions or say anything that gives the game away. That can make the conversations seem unnatural, which makes the story unsatisfying.
HP Lovecraft’s The Whisperer in Darkness has some of this problem (as I mentioned a couple of years back). The story of a man discovering alien horrors lurking in the New England hills is certainly effective, but the narrator never suspects that when his contact switches from AAAH ALIENS to Aliens Are My Friend, something might be up. He walks blindly into a trap and never grasps the obvious, all so that the final revelation can be a terrifying shock.
Like I said, I don’t run into many stories like that these days. That is definitely a good thing.