>>114329347I suspect it's because she feels like an amalgam of every mean girl type boys have a crush on in middle school, and she reminds people of their own budding adolescence. There's a desire to dominate this girl who made you feel funny as a boy or who "rejected you" in some fashion.
For many it's not even really about her character specifically, it's just more that she's an empty vessel for fulfilling some fantasy of being alpha with a girl who is both innocent and nubile, but also coy and promiscuous. Also, if you happened to be the same age as her when the show first aired, there's a chance you just have a long standing crush and it hasn't fully reconciled with you that you may be old enough now to be her father.