Saying Poison Ivy is an extremist is, to me, a way to dismiss her character as a whole. There are some depictions of her that can be labelled extremist, like in Everyone Loves Ivy, but I think such depictions do her a disservice. Many of the best depictions of Ivy are where she is a Circe-like figure: mysterious, powerful, dangerous, but also well content at peace. She is not here to tell other people what to do, as long as they don't hurt her or the things she values.
Stjepan Sejic is one of the creators who digs into this, like he recently mentioned on Twitter:
While not necessarily how I view her, it puts the spot on that Ivy is much more of a defender than someone who wants things for herself. To her, Batman is the enemy not because he stops her from getting the things she wants, but because he defends a system that encroaches on the things she considers valuable and worth defending.also, one of my headcanons is that poison ivy is most powerful when barefoot on fertile ground. suffice to say, my idea of ivy is not fond of concrete. also she can hear muted whispers of the green. not in the way swampie does but hen her rage subsides, she can hear it clearly.
unfortunately her rage is easily provoked as the very polluted air agitates her as an endless allergy. she is the vengeful incarnation of the green. nature's fury.
but when the air is clear, she is wonderful.