Now I know that for posting this I'm probably going to be instantly shot down by people far more educated about Glorantha than me, as that is the nature of this community, but considering barely anyone seems willing to try and write anything about Dragonewts I figured my theory was worth a shot.
So in the new RQ, we have a power rune tree similar to the personality pairs of Pendragon, correct? And if I'm remembering the Quickstart correctly, invoking a rune entails a potential bonus to it, correct? So, my theory is, based on the new RQ rules and a few articles on Dragonewts from the old Issaries site, that one -note I say one reason, not the only reason - of the reasons they behave so erratic and strangely is because every time one of their power runes is used and increases they are obligated by their religion to do everything in their power to rebalance it, to perform Right Action. And because dragonewts without spiritual balance are constantly trying to invoke runes their personality actually tend to be much more extreme than your average human's, resulting in extremely self-contradictory actions and unpredictable behavior patterns.