[kemayo]

Language is a living thing. The meanings of words change over time, and that's normally a helpful thing, which lets us express culturally relevant concepts.

In this case, it's pretty useful to have words which distinguish between biology and culture.

[nailer]

Totally. It's just confusing when people were already using 'gender' to distinguish XX/XY from copulation (since 'sex' means both).

[dragonwriter]

If you use “ascribed gender” and “gender identity” to describe the (external and internal, respectively) social traits, you avoid the confusion between the two and with the biological trait that comes with using bare “gender” for that purpose.