Like if I had to pick a metaphor, as I understand things, for HN, think of it an imperfect binary classification for assigned gender at birth API, a leaky abstraction on top of society understandings that are themselves constructed the messy analog physicality of people's "biological sex" which is not as simple as two options male and female, not even just in terms of chromosomal sex. Add in hormones levels, hormone sensitivity, genetic differences, brain structures, body hair etc, and even what people think of as basic "biological sex" is actually multifaceted and variable.
So in talking about gender as a construct, rather than something innate and natural and binary, it becomes possible to talk about how the API was developed, and maybe say, hey this API is a little simplistic.