Add to that the idea, which I've always subscribed to, that a deity's power comes from its worshippers - meaning it's in deity's best interests to promote itself to like-minded mortals in order to gain more followers - and designing the pantheon, the deities and the religion supporting each of those deities all at once suddenly makes a lot more sense as each is going to directly affect the others.
I find it extremely distasteful. It's a retroactive justification for why ancient deities behave like newborn evangelist cults, and it grossly diminishes their majesty. Beings that require and demand worship are, practically by definition, not worthy of it.
And then it justifies garbage like the Wall of the Faithless which makes the "Good" alignment utterly meaningless.