Is the neat categorization of humans into two discrete categories bogus?.

 'Ethnomethodology' is a sociological analysis of how individuals construct their common-sense knowledge of the world in social contexts and the resulting natural attitude about sex. 

The everyday “common-sense” about sex. It is held by those he dubbed “normals” for whom the categories male and female are exclusive, exhaustive, invariant, and applied on the basis of genitalia. Notably, part of the natural attitude involves dismissing counter-examples (e.g., intersexual individuals who show that the neat categorization of humans into two discrete categories is bogus) as abnormal and aberrant.

Some hold to the  theoretical framework that there is  a strict biological binary prior to cultural imposition and the resulting view of some that holds the much disputed and controversial view that most self-identified transgender people are predominantly men who are in some way performing stereotypical and sexist femininity.