Part of the design of the priest classes is that they are...well...priests. As such, their power depends on the whim of their deity. That necessarily places certain demands on their role-play. If you're not role-playing a good "follower of whomever", then "whomever" shouldn't be expected to give you empowerment lovin.

Non-priest classes don't depend on anyone for their skills/spells, so there is no, "must be a good follower of X" requirement on their role-play.