Honestly, from an unbiased perspective I don't see why Link can't also have a female equivalent outside of Linkle and that one BS-X Zelda game. The only game I can think of where Zelda is romantically interested in Link (as opposed to just allies or friends) is A Link Between Worlds. Maybe the answer is as simple as that it's too much effort to design two separate playable genders; not enough women really care whether the character they play as is male or female; or that Link, like Kris in Deltarune, is already "bishounen" enough to look feminine to the untrained eye, anyway. I would personally like a female Link for the two big reasons shown off in this lovely art.