Man-eater doesn't sound as bad as this one. Yet when we say man-eater, why do we include women in it? Oh history~ I love how you fool people with manliness ~
I believe we say "Man-eater" because for some reason "Human-Eater" just doesn't roll off the tongue as easily. Same could be said of "woman-eater" but it's still feels easier to voice aloud than "human-eater".
Also, I do know some incredibly manly women.
The Oka Compendium: A glorified record of my alt-a-holic-ism. May or may not be up to date at any given point.