User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-4682548-20130430234715/@comment-5020152-20130501180550

Yama Tsukami was once worshipped as a sky/earth god or something like that.

So one year, the villagers are preparing for a festival to mark the passing of Tsukami over the Tower and a group of hunters happen to stop by for a visit.

"Oh, there's a sky/earth god visiting your town? Let's go kill it!"

@Dax: Honestly, why would the Goldbeard Ceadeus be killed because it's threatening an ecosystem? He's part of an ecosystem too, you know. If he throws another ecosystem off balance, well, that's nature. Killing him could possibly throw his own ecosystem off balance, and then you'd have humans to blame (again).

And who knows - "for the sake of the ecosystem, it must be slain" could just be some propaganda to get ecologically-friendly hunters to take part in the hunt.