Because Link is just the name given to the hero in the recurring legend. It's not the same character each time and because making a female Link (whilst keeping Princess Zelda) would be interesting as a reversal of the "hero save princess" trope (that TBF, Zelda has been subverting since OoT).
I just think it would make for a good, interesting story, and I can't think of a reason why they wouldn't.
(Pissing off misogynistic fanboys is just another reason to do it in my book)







