If you read her other supports, she's actually pretty decent and helps out a lot of the other characters. Helping Gregor deal with his dead brother, Libra with his dark past, Nowi with being an immortal orphan, etc.

A lot of her fans just like her for her looks, but a lot of her detractors probably don't know much about her, either- and are just bandwagoning on the popular opinion.

There's also simply the fact that she's a very solid unit in both Awakening and Heroes.

so true it hurts.