You should read more about folklore of different nations. As for the Witcher, it is a slavic game based on slavic book based on slavic folklore. Slavic culture has a lot of good creatures that are ugly and a lot of bad creatures which are beautiful, and vice-versa as well.
@Beastwolf: Well, they were driven away by mankind and their Witchers. Though Geralt isn't the classic "monster genocider" most Witchers were, they still bear some resentment. See TW3 quest Contract: Skellige's Most Wanted.
i forgot do CD projekt games tend to get "modkits"(tools for making mods, like what most Bethesda games rely on now for customers :P) or not? because if they do eventually someone will probably mod it like the Moe-fans want.
I'm personally very glad that in TW3 not everything friendly is cute and pretty and not everything hostile is ugly and disgusting. I'm sick of these tropes.