Earlier quoted context omitted.
Nothing justifies threats. But in this case, the reasons that this would offend people -- that it makes untrue and unfair accusations about a real-world case-- are true. Or even worse than one would assume, even, in that it's not autobiographical and does the same about identifiable third parties.
It does not in fact make untrue and unfair accusations about a real world case. It is a work of fiction. Until this Slate article came out, there were, like, 4 people in the world that know about the story's inspiration.
It's a #MeToo era-story which is used to narrate supposedly 'real world threats'.
The reason that some might be upset, is because you have a real world story of a 'nice guy' - who was used as the basis to narrative a story about how 'men are bad' aka a warning about 'toxic masculinity' etc..
Here is 'The Atlantic's headline of the original 2017 publication:
"The depiction of uncomfortable romance in "Cat Person" seems to resonate with countless women." [1]
Here is NPR's headline:
"'Cat Person' Author's New Book Evokes #MeToo Themes" [2]
WaPo:
"Opinion: ‘Cat Person’ is a next step in the #MeToo movement" [3]
So that's literally the first three pieces that came up in the Google search - and those three publications are 'major, respected, institutions'. All three are using the 'creative fiction' to promote a narrative about men's supposed actions etc..
It's obviously not just about 'some random bit of fiction that happened to be about real people and those real people are upset'.
If this was Stephen King, who used his 'Real Life Doctor' as the inspiration for some diabolical character - that would be the story. But there wouldn't be any elevation of the story into some kind of narrative in that case ... so it'd just be about a possibly upset Doctor.
[1] https://www.theatlantic.com/technology/archive/2017/12/a-vir...
[2] https://www.npr.org/2019/01/13/684894872/cat-person-author-s...
[3] https://www.washingtonpost.com/blogs/post-partisan/wp/2017/1...
Edit:
Here's a gem [4] it's literally an academic publication using the original story as basis for describing narcissism in the role of the oppression of women.
"I argue that Beauvoir’s notion of narcissism is an important tool for feminists today—well beyond the interpretation of Cat Person. It presses us to see systematic subordination not just as something done to women, but also as something women do to themselves. This in turn highlights the neglected role of self-transformation as a key aspect of feminist political resistance."
This is pseudo-intellectual hyperbole (published!) over a story that amounts to a giant lie.
It's intellectual bigotry.
[4] https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&c...