If you want a surefire way to kill your story and slay any interest a potential reader will have in it, let the plot drive.
Looking back on some of the books I’ve read in my formative years, a host of franchised novels many of which I’m likely to donate to a library when I move, I realize that only a few are truly driven by character growth and conflict. A good story based around characters, like Brave (here reviewed brilliantly by Julie Summerell), many of the later Dresden novels, or Chuck Wendig’s Bad Blood (the sequel to Double Dead, short version: almost as good as the full-length novel), doesn’t need all that much of a plot. If a character is going through a change, and that change is going to be opposed for some reason, you have plenty of fuel for conflict, drama, interaction – story. The narrative will breathe without assistance. The tale will live.
If, on the other hand, your story is the product of some non-character formula or relies on contrivance, the result will not be as favorable. I’ve seen it happen in lots of stories. Usually, you can see it coming. When technobabble or new powers as the plot demands or deus ex machina moments begin to crop up more and more, it’s sign that the story has a terminal illness. The execution of the plot means the execution of the story, hooded-headsman style, as potential interest and characters put their necks on the block to feed the axe of convenience.
The story may click along without fault or pause, merrily going from one plot point to the next as if nothing’s wrong, but if there’s no characterization beyond the very basics, if the conflict isn’t rooted in our characters and what makes them who they are, the story has no life of its own. A lot of video games have this problem. Lacking character depth, they move the player from one set piece to the next with the certainty of a commuter rail line. A game like Portal can get away with this because of good writing, characterization, and unique gameplay, but something like Space Marine has to work extra hard to overcome this problem.
I guess what I’m saying is this: if you want to tell a story, your characters are your most important allies. Even if you hate some them, even if you know some are going to die horribly, spend time with them and make sure you know them before you approach your plot. Get the balance wrong, or make the characters little more than cogs in the plot’s machine, and the metaphorical headsman will be waiting.