I agree, but many Zoroastrians would disagree that it's dualist.
I have a couple of Zoroastrian friends i've conversed with on the topic and they generally think that it's not dualist by any means. However, what's interesting is that Evil has "created" certain animals like the Snake.
I thought that Islam pretty much wiped out Zoroastrianism --- how many people still follow this? I read somewhere on FR that the 3 magis were Zoroastrians --- I thought that was pretty interesting.