hehe...I hear you and agree. Specifically, I think that open or blatent real-world religion parallels don't work (i.e. christian/muslim conflict in GURPS fantasy setting) well and appeal to the masses. Personally, I find it cool. I am a history buff and so find it extremely interesting myself.
I think that you can take real-world religious parallels and transform them into a fantasy campaign like you did with your dwarves. There is an obvious real-world parallel there. Those outside the dwarven culture would just think that the dwarves are crazy because they don't understand the foundation for the eminty between dwarven religious factions. I really like your campaign idea for the dwarven culture. I like dwarves!