edit: to the coward who deleted their response, this is absolutely, 100% serious. a "satirical" response would have been something along the lines of "a free and open internet which is accessible to all will contain content that can be disagreeable to some. the alternative to this is a closed, exclusive club that is antithetical to the goals of the internet. if you don't like the dumb library, don't use it."
Separation of code and packaging/distribution
Using is-odd is fine, the same as developers using the "+" is fine in languages that support it. Where JS is weird is in not having a full standard library along with very arbitrary data, leading to folks seeing that they use the is-odd functionality regularly enough to where it's useful to have a dedicated operator
I'd use an is-odd library if I need to figure out if something is odd across 20 different data types depending on how somebody inputted data in a UI
And then other devs feel the need to use the package rather than copy a code snippet.
The fact that "is-odd" exists is just silliness. It's a joke. The fact that it has nearly half a million WEEKLY downloads should absolutely horrify you. Any developer that uses the "is-odd" package is wholly unqualified to be coding and needs to get a refund from boot camp that "trained" them.