Implicit in every argument that the narrative-- fluff-- description of a class is not rules-relevant and that classes only describe the discrete mechanical abilities of the class is an argument that they should be allowed to play like that at any table they sit down to. They are just as much trying to tell other people how they have to play, even more arrogantly and sanctimoniously than the people arguing for consistency in their games' magic/powers systems.Why does it matter how other people play the game at their tables?
"Sure, go ahead and play the game as wrong as you want to."
Personally... I do not have a problem with divine magic being the exclusive province of Da Gawdz (I have hella problems with how D&D does this, but thats a different argument), with Da Gawdz granting every individual spell or with Da Gawdz granting a one-time clerical Investiture, or with the (IMO overly complicated) 1e rules described upthread. I don't have a problem with divine magic coming from the elemental-flavored kami or from the Primoridal Spirits of ruined Athas. I don't even have a problem with Clerics of philosophical ideals or the Mystaran Spheres, or even just "divine" magic just being a "White Magic" tradition compared to Wizards and Warlocks.
I just think that's a decision that should be made at the setting level, at the decision to design or play in any given official, third-party, or homebrew setting. The Forgotten Realms and Greyhawk are crystal clear on this matter, Dark Sun and Legend of the Five Rings are crystal clear on this matter... and if you want to "make an exception" you're not playing FR/GH or DS or L5R anymore, and that's fine but if I'm going to play in a homebrew setting, I'd prefer to play in a setting homebrewed whole.
A "Cleric" is a defined object, not just in the game rules, but in every game world that is based upon those rules. This trend to divorce every rules-object from its corresponding world-object is not good for the game, not even for the games of the people pushing it because it renders everything in the game-- you guessed it-- incoherent.