I mean, there’s also historical context to be considered here. Throughout history (and still today in many places) women have been treated as subhuman, or at least as lesser to men; in many cultures, married women were literally considered the chattel of their husbands. In that context, using the term “female” which almost explicitly carries no connotations of personhood feels a lot more like a hateful slur. I don’t think “male” really carries that same historical baggage, though.