Você faz alguns bons pontos, tanto que eu quase me sinto compelido a concordar com você. Na verdade, uma versão minha de alguns anos atrás provavelmente teria escrito algo exatamente como isso...

That being said, the word gender, has become something new entirely or more correctly said-- It's becoming something new. 

Language, as we know is always evolving or mutating, depends on how you want to look at it.

When I was a young lad, gender and sex were basically the same thing, or at least used interchangeably in all mediums, but these two words began drifting apart many years ago, long before we were probably aware of it.

I'm with you when you say that it's truly not definable, and if we want to speak clearly our current understanding of this word and it's usage makes it close to impossible. However, this will not always be the case, and when the dust settles the word and it's usage will not only be common knowledge, most people won't even be aware there was a debate over this (as it has happened countless times in the past)

Like you, I tend to overthink these subjects a lot. The eternal quest for clarity is never a waste of time, but there's a "risk", if you will, when we explore these subjects that we ought to consider.

We can, and I say this because I've done this myself, provide an "intellectual" reason to be unempathetic to the plea of the minority groups where these debates are not just intellectual exercises, but real explorations into their right to exist.

I should end by saying, thank you for writing this, I enjoyed thinking about this very much.

Cheers