I thought it was just a more scientific classification.
Scientifc classification by sex. Referring to others by their biological sex in a social context is weird and creepy. Even if you believe sex and gender are the same thing, it’s still weird to call people by their sex. “Hello, male human. Want to ingest some fried pieces of cow flesh tonight?”
Like all Romance languages, number “one” has different masculine and feminine forms, depending on what you’re counting. Unlike other Romance languages, number “two” is also gendered.