The classification you've described is not valid for use with Homo sapiens, neither today nor in the future. It's based on the assumption that our genes control our organs, when they're merely a weighted suggestion at best. And, the Y chromosome is gradually withering away in humankind and is expected to disappear someday. Human beings can develop fertile male reproductive organs without it (see below), and evolution abhors exceptions that have no benefit and many drawbacks (such as colorblindness).
> a simpler classification system: XX = female, XY = male
This would, as with all other such systems that refer to X/Y chromosomes, be invalidated immediately upon contact with reality. I estimate that a couple million people worldwide have one set of fertile reproductive organs that do not match the binary view described – that is: men without, and women with, a Y chromosome.
> it's only complex because we (collectively) decided to complicate it in order to accommodate the preferences of small subsets of society
None of these people selected a "preference" at birth, and may go their entire lives and have children without ever realizing that their chromosomes and their reproductive organs do not match the XX/XY binary you've presented.
> anything else = unclassified (genetic defect handled on a case-by-case basis)
This would mislabel XXX, XXY, XYY people as "defects" for genetic circumstances that do not necessarily have any visible presentation, that people may not be aware of at all.
It also mislabel some, but not all, intersex people as "defects". Intersex people span the entire spectrum of known chromosome combinations in human beings: Human bodies produce one or more sets of (often) fertile reproductive equipment regardless of what chromosomes are or are not present.
Ironically, then, focusing on XX/XY classifications while disregarding the realities of human biology always results in an invalid classification system that is more likely to harm cis people than intersex people.
> a simpler classification system: XX = female, XY = male
This would, as with all other such systems that refer to X/Y chromosomes, be invalidated immediately upon contact with reality. I estimate that a couple million people worldwide have one set of fertile reproductive organs that do not match the binary view described – that is: men without, and women with, a Y chromosome.
> it's only complex because we (collectively) decided to complicate it in order to accommodate the preferences of small subsets of society
None of these people selected a "preference" at birth, and may go their entire lives and have children without ever realizing that their chromosomes and their reproductive organs do not match the XX/XY binary you've presented.
> anything else = unclassified (genetic defect handled on a case-by-case basis)
This would mislabel XXX, XXY, XYY people as "defects" for genetic circumstances that do not necessarily have any visible presentation, that people may not be aware of at all.
It also mislabel some, but not all, intersex people as "defects". Intersex people span the entire spectrum of known chromosome combinations in human beings: Human bodies produce one or more sets of (often) fertile reproductive equipment regardless of what chromosomes are or are not present.
Ironically, then, focusing on XX/XY classifications while disregarding the realities of human biology always results in an invalid classification system that is more likely to harm cis people than intersex people.