Are you saying there is no reason to play without a guaranteed complete victory?
No, I'm saying there's probably some sort of middle ground.
Which I think is what Korgoth was saying as well. . . .
I agree with the OP. I think we all come to the table with characters that reflect something we want to experience, whether gritty or glorious. The more the GM delivers that experience, the more fulfilling the game will be.
Nobody finds a hollow, obviously preordained victory fulfilling. We all want challenge. But I don't believe very many people
really come to the RPG table looking for a pure test of their tactical skills--that psychographic plays Magic: the Gathering instead.
The middle ground accepts that Batman will likely prevail--yes, largely because he is Batman and he is the protagonist, and we expect the protagonist to prevail in an RPG just like we expect it in a comic, novel, or movie. (As a PC, Batman's dramatic expectation is backed by the game system, which in almost every game (save CoC and maybe Dark Heresy) gives the PCs a statistical advantage over the adversaries they are expected to face.)
The middle ground then expects the game to provide challenges and surprises and dramatic ebb and flow--moments when prevailing is thrown into doubt. Just like in a movie or novel, this doubt can exist even when, objectively, we're pretty certain the heroes will find a way to win.
Going back to Korgoth's post, if I had to choose between the two options, well, I'd quit playing RPGs.