Mortal Psychology, Viewpoint Shift
Mortals would only revere the divine when it was a concept out of reach.
But when it became an attainable goal, any form of awe or reverence would naturally vanish. As Kong Xiang predicted, this happened to be the case when cultivation was introduced to the natives of the planet. All that was needed was that tiny seed of ambition. And humans, both young and old, did not lack that inherent quality.
But still, habitual devotion was hard to get rid of, so at the beginning, the older generation were not really inclined to believe the grandiose claims that ordinary humans could gain mystical abilities, such as flying, smashing boulders to smithereens with a punch, and cultivating the so-called Dao, upon venturing into the path of cultivation. Such, they argued, was supposed to be the domain of the deities.