1/ People always get hung up on the word "binary" in relation to biological sex. Sex is still binary even if some people may be truly sexually ambiguous and cannot be classified as either male or female.
Here's an analogy using a population of yellow (
) and white (
) flowers.
Here's an analogy using a population of yellow (


2/ Imagine this population consists of plants with flowers that are ONLY yellow or white, no other or in-between colors. Now suppose some of these plants have a mutation that prevents them from making a flower (
).
Our population:





















Our population:





















3/ In this system, FLOWER COLOR is binary—there are ONLY 2 flower colors: yellow and white.
"BuT sOme PlAnTs doN'T HavE yEllOw oR WhIte FLoweRS So iT CaN'T bE BinARy!"
This is a completely irrelevant statement that does not negate the binary nature of flower color here.
"BuT sOme PlAnTs doN'T HavE yEllOw oR WhIte FLoweRS So iT CaN'T bE BinARy!"

This is a completely irrelevant statement that does not negate the binary nature of flower color here.
4/ Personally, if use of the word "binary" in relation to biological sex is a major stumbling block and causes so much confusion, then I am happy to ditch it.
If you insist that "sex is binary" HAS to mean that every human in existence MUST be either male or female, fine.
If you insist that "sex is binary" HAS to mean that every human in existence MUST be either male or female, fine.
5/ If that's what you insist it must mean, then sure, sex isn't binary. But this is just a stubborn way to refute the noise I am attaching to a concept without actually refuting the concept I am trying to convey, which is that there are 2 and only 2 sexes in humans.
6/ So I'll agree that, according to your strange and stubborn ad hoc framing, sex isn't binary, as long as you agree that in humans there are 2 and only 2 biological sexes. Because that's the *concept* I care about conveying, words be damned.
Deal?
Deal?
7/ Oops, apparently for iPhone users ALL the flowers are yellow! 
https://twitter.com/scttfrnks/status/1357606397219753985?s=20

https://twitter.com/scttfrnks/status/1357606397219753985?s=20