> Nature is simply saying: don't study social constructs, it's not scientific, a phrase with which I think I loosely agree
A lot of the time, when someone in the Humanities use the term "Social Construct" they mean a categorization scheme that have overlapping categories, especially when used by someone in a way they don't like.
Someone with some level of understanding of natural science knows that this problem apply applies to a multitude of category schemes, if not most. In biology, one could argue that our definition of a "species" is a social construct. Even alive today, there are plenty of animals that exist on a continuum between different "species", and over evolutionary time, every living organism exists on this same continuum, and at the start, there were even no clear distinction between living and non-living.
The person in the Humanities like to use the word "essentialism", while still giving Humans special knowledge, when in reality we all live on a continuum that includes monkeys, fish, rocks and oceans. We're all recombinations of atoms and ions.
Still, there ARE clear and real patterns in this madness, and most of science is precisely about understanding these patterns. While we DO exist on a continuum, most of the continuum is empty, and especially if we consider only one snapshot of time.
A biologist can talk about "tigers" without making an effort to consider ligers and tigons, or pre-historic ancestors of modern-day tigers that were similar but not identical to modern tigers.
Biologists will also use the terms male and female tigers, knowing that the intermediaries are vanishingly rare. The continuum between them is there, but mostly empty.
Or a physicist may even speak about a "red" laser, knowing perfectly well that the wavelength used to separate "red" from "orange" is a "human construct".
So, if someone claims that "biological sex" is a human construct, they may be correct in some uninteresting way, but are primarily just obfuscating.