Mezuka
Hero
It is a fictional religion. My group is all non-religious we played it like we played any religion (god) in D&D. Clerics pray for spells. Praying once in a while to get a re-roll is not something we find difficult or uncomfortable.Seems like nearly all dislike is for the setting and not the game.
And isn't the religion purely fictional? The closest thing I can think of are the Japanese seven fortune gods, which seem to have a roughly similar concept.