I don't know what's so hard to understand about this; they're non-human monsters for goodness sake!! That alone leaves enough basis for a character to assume them hostile until proven peaceful. And when you add a religion founded as a response to Beluaterra into the mix then the whole matter seems perfectly logical (at least to the medieval mind).
We have whole families/realms despising entire human realms/families and all affiliated due to longstanding feuds, yet when a religion speaks against a race of dubious non-humans because of similarities with a group that attempted to destroy a whole continent they are "irrational"?
