Wow.  This is getting complicated.

A white skinned woman with an afro leading the NAACP gets called out and ridiculed for self-identifying as black, even though she lived/breathed "black" and advocated for the race exhaustively.

Someone with 1/64th aboriginal lineage can claim Indigenous status, but someone else who knows aboriginal cultures quite well can't even write fiction about it (let alone wear a Halloween costume) without being accused of "cultural appropriation".  

Yet it's fine to pick and choose your gender, or lack of gender, or fluid gender, or whatever, and this is somehow a legal right?

If gender is indeed a social construct, independent of biology, then how can race be any different?