I wasn't complaining about OOCness, I was complaining about their turning the only female villainess in Batman's rogue gallery into a character I don't find remotely interesting nor compelling.
To me, Ivy the cheerful serial killer who kidnaps and tortures innocent people to death for crap and giggle, just doesn't work. Not because she is OOC, no. But simply because I find that kind of Joker-like villains boring at best and incredibly frustrating at worst (because on the long run they make the heroes look ineffectual).