An alternative "Occult Universe"
I open my occult detective novel in what is ostensibly a "noir" style, but through worldbuilding I attempt to show that the story is set in an alternate occult universe which diverged from our own sometime during the early 19th Century, along with the rise in Victorian-era occultism. Paranormal phenomena always existed but was ephemeral up until the industrial revolution.
In this world, paranormal phenomena can be induced in steel similar to magnetism. It's comparable to steampunk where steam engines and clockwork mechanics are handwaved into modern-day (or impossible) technology. Here, paranormal effects have been induced into mass-produced industrial items. The process is not explained but it's coded as bad for the environment, experimental, and generally unreliable as the phenomena uses poorly understood "occult logic". The worldbuilding also sets up a countercurrent motif that the paranormal on an industrial scale has undesirable consequences, like the backlash against nuclear power – it's a leap forward when it works, but you wouldn't want to be nearby in a catastrophe.
For the characters, these occult-powered industrial items (gasoline-free luxury cars, levitating trains, city power plants, military weapons) are a routine part of life, symbols of wealth and power-disparity that compliment the noir themes of political corruption, greed, abuse of power, secret societies, etc. I'm introducing them as "things that exist" matter-of-factly, and layering them with coded sinister adjectives: hovercar engines make disturbing human throat sounds, "ghost" trains slither in the night, etc.
My problem is that beta readers are questioning this aspect of the world and calling it "sci-fi". They aren't critical exactly, but it clearly feels non-sequitur. Rather than seeing the paranormal as a transformative "technology" that has corrupted society (a metaphor for pollution, industrialization, consumerism), readers see it as an extra "buy in" that doesn't fit the rest of the story. My plan was to have a naive character begin to question these "toxic" items, transitioning from symbols of wealth to symbols of moral corruption.
In the Writing Excuses podcast How Weird is too Weird, they suggest the reader will accept 1 "buy" for the world and everything else should derive from that. A story with multiple unrelated "buys" will seem unfocused, trying to do too much at once. I've fallen into that problem.
My "buy" is that paranormal phenomenon can be induced in a manufactured object. The industrial machines exist, unexplained, but they are the logical worldbuilding conclusion of this idea. However, the story's MacGuffin is about a manufactured object with much smaller stakes, its purpose is evil but personal: an occult Maltese Falcon that might grant a kind of immortality. Immortality effects 1 person, flying cars effects all of society and seems like a much grander theme that is being ignored.
Part of the problem is that I am trying to introduce a sub-genre with unclear rules. There is no "occultpunk" for the reader to fill in the blanks about what is normal in this world. I have an 800lb worldbuilding gorilla that readers feel should have more of a payoff in the story. I would like to keep this aspect of my world, I think it is interesting, but not if it's a distraction.
How can I get readers to accept more than 1 "buy"?
Is there a way I can better integrate this concept into the story, or has my worldbuilding gone off the rails? Can I get readers to "buy" this grand concept as a backdrop, and still appreciate the smaller paranormal MacGuffin as a threat deserving its own story?
It also breaks my own rule that paranormal stories need a firm normal to contrast against, otherwise it obscures why the paranormal thing is suppose to be interesting. Maybe I should avoid grand-concept worldbuilding altogether? Readers calling it "sci-fi" indicates it's sticking out in an oddball way. They don't see the rest of the story as taking place in a sci-fi universe, but they mention those elements like they are refugees from the wrong genre.