Yeah, no, the story is unsalvageable. At the end of the day, it's a very poor mishmash of the plots of Fallout 1 and 2 mixed with horrendous dialogue and writing. No writer in this world could salvage it, no matter how hard they tried.
As the saying goes, saying it doesn't make it so.
Yes, the game's dialogue is poor, the world building found within the game is nonsensical, and the plot of the game suffers overall, all due to Emil not being able to consistently tell a story if his life depended on it, but the base is still there and can absolutely be adapted into a 1-2 hour movie. Off the top of my head I can think of a few ways to adapt the game into a movie:
1) Center the movie on James rather than his son, as James is the main character of the story to begin with. Have the story follow his journey through the Capital Wasteland.
2) Throw out the characters of the Lone Wanderer and James all together, and make a war movie about the Brotherhood of Steel's war against the Enclave in D.C. over Project Purity, which in the film would be an Enclave invention made to kill off the population with perhaps James as the big bad guy.
3) Incorporate the DLCs, and you could easily make a trilogy of films based off Fallout 3 alone in the style of old pulp stories about a post-nuclear world with different characters and scenarios.
4) Hell, roll all ideas above into one, and you could start a franchise of films. An adaption allows for you to quite literally do anything you want with the source material, no matter how shit it is.
As for it being a mishmash of Fallout 1 and 2, no one's disagreeing with that, but I think that actually benefits a short format story like a Hollywood movie. Hollywood execs and the mainstream audience doesn't care that Fallout 3 is a mix of 1 and 2's plots, that's something for us as fans to bitch and moan about. The reason we're getting this Borderland's looking Fallout show in the first place is precisely because of that.
You say narrow-minded and spiteful, i say i'm being realistic.
I'd say you're being more hyperbolic than realistic when it comes to this, but let's agree to disagree.
Coming up with an entirely new story takes far less work than trying to adapt the vomit Fallout 3 calls a story.
This I can agree with. Not because Fallout 3 is unadaptable, but because most writers would rather do something new if given the chance then retread what's been done.