Yeah, you only get one of these. Pick.
Those two statements aren't mutually exclusive. For more than 99.999% of people their genitals accurately depict their chromosomal composition. You are, once again, arguing that an obscure exception serves to invalidate the rule.
While I grant that 46,XY isn't the only chromosomal disorder which results in ambiguous genital formation, it is far more rare with other configurations, such as in androgen insensitivity.
Outliers absolutely exist. Just like they exist with our theories of the universe. I'm standing strong with my definition. XY = male; XX = female. Anyone outside of these are the rare exception and belong to neither sex. You can't just assign someone a sex because you feel like it. In fact, pigeon-holing people into a sex when they don't identify with either seems kind of bigoted to me.
To use your analogy, you're insisting relativity isn't a thing because Newton's laws work fine in most situations.
That is the exact opposite of what I'm saying. I'm saying that the law of relativity exists despite being unable to reconcile exceptional conditions.
As for, "and you're still telling women who have given birth to use the men's room", I am aware of not a single instance in history where a person was born with XY chromosomes and successfully gave birth. Could you cite that please?
And for maximum comedy, you're potentially telling an XX trans women that...yeah you're model kind of explodes here, because you designed it to exclude trans women, but here we have a trans woman that fits your definition.
My "model" doesn't "explode" here because I think that a XX person is a female and should be using the female restrooms.
I am well aware of Buck Angel. I am supportive of his lifestyle choices, however, he is, undeniably, female. If women want to use testosterone to build muscle mass and change their appearance, I am wholly supportive of that. They should still be using the female restrooms. Or are you telling me that female bodybuilders should be banned from women's restrooms now?
Meanwhile I could line up three women for you: Two cis, one trans. One 'normal', one CAIS, one early transition post-op trans. And you wouldn't be able to tell the difference between the three without a very very close exam, and even then not unless you knew what you were looking for.
I'm sure you could. I could line up three black holes for you and you wouldn't be able to reconcile our current gravitational models. GRAVITY NO LONGER EXISTS!