Which you have replaced with "the law from on high" as spoken by you, regardless of the enjoyment of the group as a whole?
Before I begin stating how I disagree with you, let me emphasize that my statement was phased specifically as a retort in mock-diaglo mindset. In actually, I wasn't/wouldn't deriding the players. They are good players overall, and the whole issue could have been avoided if the PHB better emphasized the DMs role in establishing the prevailing cosmology. The game should serve the players, not the players the game.
That said: I am sorry to have to differ with you, but it is the GMs duty and responsibility to provide the enviroment for the players. When the books facilitate in this endeavor, this is good. When they are intrusive in this endeavor, it is bad.
It seems like your players can't contribute to your world except by filling the roles that you've laid out and approved.
They sure can contribute -- if they are willing to create a divinity that works with the existing cosmology; I don't allow players to insist I use a deity from another setting (and I have had them try). I allow players to make suggestions. In fact, my closest accomodation to this godless cleric thing is that I allow the player to define a minor power/demigod that fits a role closer to that the player desires if none of the presented ones will do. In my game, the pantheon of deities that exists is extensive like some animist faiths, with thousands of powerful spirits worthy of being called demigods and capable of granting spells.
But I as the GM reserve the final say on what it appropriate, and I am not going to write something into the game that is inconsistanct with the cosmology as it is defined. Large aspects of the campaign are based around the idea of the pantheons, the divine compact that exists between them, and their relationship with the world as it exists.
Just to clarify your policy here, if someone wanted to play a non cleric class with an alternate religion (say a small one centered in their home village) would you reject that even as a background choice with no impact on the stats?
What do you mean "non cleric class". Non divine spellcasters can beleive anything they want; it is not going to have a bona fide impact on the game beyond their behavior. Divine spellcasters of all stripes, though, need to get their divine power from a divine source; the concept of the faith itself generating the power is simply not part of my cosmology, at least not directly. Faith is power that divinities can use, but IMC, expecting faith alone to power spells is like expecting a full can of gas to cruise down the road like a car. You are missing a necessary intermediate step.