I was literally just thinking about this yesterday! It's a trend I've seen a LOT in recent years in lit crit, particularly when discussing fantasy.
I think it particularly comes up the moment an author includes any sort of marginalisation/oppression for their fictional/fantasy world. I've lost count of the times now where I've seen people read a book on, say, the terrible oppression of the Gwyllion, and immediately gone "Oh, so the Gwyllion are a metaphor for the real world X people, either deliberately or accidentally through the author's inherent racism. This is therefore super problematic because the Gwyllion are also described as Y, which means the author is also saying that about X people."
There will always be real world parallels when discussing oppression. Always. But that's because oppression is oppression - precise details may vary, but it follows the same pathways the world over, and that will naturally be copied into fiction as well. This does not mean the author is intentionally telling the exact allegory that you've projected onto it. If that's how you read everything, then yeah, everything becomes super problematic, but also, why are you reading any fiction that isn't solely about real world historical events? It's clearly not for you
And, you know, obviously there are works that are racist/misogynistic/etc, including deliberately so. But I really don't like the way people have started going "I have spotted a PROBLEMATIC ALLEGORY here, I'm ever so smart" and acting like they're the cleverest little critic that ever lived. You have to meet a work on its own terms. Lovecraft was a big ole racist, sure. Someone who has written a book about the oppression of magic users in their fantasy world, however, is rarely writing a story about how queerness lurks in family lines and must be controlled; they are way more commonly writing a story about a world with magic that they then wanted to take seriously, and while there might well be elements of queerness there, those magic users are not a 1:1 replacement.
Sometimes these lines are blurry! But we're going way too far to one end of that spectrum
The post that got me thinking about this yesterday was someone talking about how they'd love to write a vampire story exploring vampirism as a disability (dependence on a substance to manage the condition, blindness/weakness in daytime, can't enter buildings without accommodation, etc). But, they said, they can't, because they don't want to be making the point that disabled people are parasites, and vampires are generally considered parasitic.
And like. What an incredible shame. That we'll lose that, because they're already afraid of the "I have spotted a PROBLEMATIC ALLEGORY" crowd. That would be a great story for exploring disability themes, OR just a great new take on vampires, and either of those things would be so good to read. But there would be so many people who would jump in with "So you think disabled people are draining the life force of the ableds around them?", never stopping to actually think "Vampires are not a 1:1 stand in for real world disability because they are fictional and do not exist."
Anyway sorry I've rambled here, not sure how coherent I'm being. But yes, I was thinking about this just yesterday! Wild.