What is recognisable, in the fiction, is that this warrior is implacable. Why? Because they're fierce, well-trained, or whatever other backstory takes the player's fancy.I agree that PC or NPC is not a property of the character in the fiction, and yet it's treated as if it was when the PC has access to options that NPCs don't, by virtue of nothing other than the fact that they are a PC. If the NPCs are built differently, and don't have access to the same powers that the PCs have, then if we accept the premise that those powers have an in-game aspect which the characters can recognize (on some level, at least), then their being PCs is making an in-character difference...but in a way that has no aspect which is recognized in the narrative, creating a disconnect.
The thing you're saying is a central conceit of RPGs is not a conceit of Gygax's AD&D (as per the quote upthread), nor of Tunnels & Trolls, nor of Classic Traveller. It is a conceit of Runequest, C&S and Rolemaster.Again, it's not "trouble understanding," it's discomfort with the fact that 4E is so casual about dismissing and altering the concept of the narrative connection between the in-game results of the mechanics being used. Calling it an "imposition" strikes me as mischaracterizing the entirely reasonable expectation that such a thing would be a central conceit, if not for an RPG in general, then at least for one calling itself Dungeons & Dragons, which prior to that was entirely comfortable playing up that connection (and at least trying, in my opinion, to obfuscate instances of it not quite being able to bridge a gap between the fluff and the crunch).
Part of what I like about 4e is that it takes Gygax's ideas and uses them to build a game which is freed of nonsense like Cure Light Wounds being able to restore the critically injured while Cure Critical Wounds cannot even restore all of a Lord's light scratches. It takes his design to it's full potential.
When I want to play a game that takes a different approach to the relationship between fiction and mechanics, I play that.