Yes, and I'm not sure why he's getting downvoted. This is a legitimate Facebook feature.
Gender can be either Male, Female, or Custom, and Facebook gives you the option to choose which gender pronouns you prefer. Thus, to see it represented as a boolean is unusual. I'm curious as to what the value of that field is when a user has chosen Facebook's custom gender display options.
'Custom' wouldn't work in Tinder. They should have at least a third option but considering they show matches based on a gender preference having dozens of gender options will make the app quite useless as you'll be spreading people who would be interested in each other but use different terms to describe their gender into a wide variety of groups.
Are you claiming that it's equal to either only male, or only female? If not, then how exactly would you provide the information that an organism is both with a single required bit, where 0 is defined as female, and 1 as male?
I was attracted to hard sciences because the subjectivity of things like psychology turned me off. Statements like yours make me concerned that liberal arts departments are going to try to make science fit their narrative. The roles of male and female is one of the most universally common behaviors across specifies. If I grew a vagina and had a baby it doesn't make me a different gender. It means I took on some of the attributes of a human female. At that point I wouldn't consider myself male or female. But I certainly wouldn't try to make up a 3rd gender for my unique situation.
That's a very positivist approach, and I hope the liberal arts continue to erode such binary based thinking in the sciences as I believe that philosophy makes better scientists. . And so what if you "made up" another gender? Gender is socially constructed and is not a real, concrete construct. I'm sorry that considering concepts and people as unable to be hyper taxonomized by artificial constraints is inconvenient to you and more valuable than treating the identities of others with respect.
(1) Are there more than two gender identities? Yes.
(2) Are there more than two socially ascribed genders? Yes, given that (1) has achieved a significant degree of acceptance, as has aligning ascribed gender with identity.
(3) Are there more than two grammatical genders? Depends on the language.
(4) Are there more than two arrangements of sex-related biological traits? Yes
(5) Are there more than two of any of the items in #1, #2, or #4 on which people might preferences that would be relevant in a dating app? Probably.
The commenter your responding to is most likely using "gender" to refer to the concept you would describe as "sex". That is, the biological characteristic of being male or female rather than a grammatical concept.
A trait either is binary or is not (being binary is, itself, binary.) A trait that the vast majority of the time takes on one of two values, but other times takes on other values, is not binary.