There must be a corresponding reason for any Godfall; this is a very common view. The deities Shard has encountered in the past all indeed had their own reasons for showing themselves. For example, the God of Gambling came in response to Mr. Riddle's gambling invitation; the Vampire God descended to hold a banquet; and the God of the Journey looked forward to interesting travel stories.
But once he thought of that, the question of why the Old God "Golden Sovereign" appeared at the "Black Mist Camp" suddenly became something worth carefully pondering.
The things those higher-dimensional beings take a fancy to are very different from what mortals desire. Take for instance the "Vampire Duke Lowell," who has interacted with Shard several times: he laid out plans across two Eras just for a single cup of Blood Brew and wanted nothing else. From a mortal's point of view, this is completely incomprehensible.
