How is that not a sufficient answer? If Nolan's Batman was going to come out of retirement, that's why he would do so. To help people.
Which was the main reason he became Batman in the first place, psychological elements notwithstanding. To help people/Gotham.
That's not what was shown in The Dark Knight Rises. Batman came out of retirement because he needed a reason to justify being Batman. In this case, **** literally hits the fan when Bane comes to Gotham.
This isn't to say helping people is not important, because Bruce cares about helping. But it's not his primary reason for being Batman. In fact, Goyer and Nolan both said that this Batman treats the persona almost like an addiction. In fact, Batman exists because it's Bruce Wayne's purpose for existing (taken to the extreme). That's the main reason above all else. It makes more sense when you place the scene of him overcoming the Pit in this context. The whole point of that is to show how Batman isn't Bruce's
only purpose in life, life in and of itself should be the reason why you're motivated.
There's absolutely nothing in THE DARK KNIGHT RISES to suggest he would never potentially take up the cape/cowl again. And even if there was something like that, Batman, like any human being, can change his mind.
I never said it was present in TDKR (and even then, it's present there too), I said it was present in the entire TDKT. In Batman Begins and The Dark Knight, Rachel tells Bruce that as long as he's Batman, they can never be together, and yet we see that Bruce is willing to throw away Batman (scene where Harvey confesses that he's Batman) so that he can have a normal life. Bruce certainly worked hard to make sure he could have a life past the cape and cowl, that ultimately leads him to a kind of purposelessness after The Dark Knight.
Heck, the Dark Knight had a simple minute where Natascha asks Harvey if he'd be up to replace Batman as Gotham's hero. Since you mentioned TDKR, there was also a moment between Alfred and Bruce where Alfred reminded Bruce that he's not Batman anymore, and that it's time to move on (BB-TDKR: "I've never given up on you" in conjunction with "I wanted something more for you...I still do"). I think that's more than enough to show that Nolan's Batman, or rather, Bruce Wayne was never meant to be a permanent hero.
The whole "Bruce Wayne died with his parents" approach is popular, but I don't find it very interesting, or remotely deep.
Yes, he underwent trauma, but to say that that trauma simply ended the existence of "Bruce Wayne" is incredibly cheap psychologically speaking.
I find the concept that "Batman" was born when Bruce's parents died, Bruce Wayne didn't die and Bruce had to balance the two impulses and aspects of his personality (more than just a secret identity) and a huge change to his life to be infinitely more interesting. The idea that a traumatized young Bruce dedicated his life to this idea, this mission, and actually GOT THERE and sustained it despite all odds is a WHOLE lot more compelling for me than "well, I've got nothing else to live for, might as well do this". And pretty much all the elements Nolan focused on (Bruce needing to be Batman, Batman as penance, Batman as an outlet, addiction the mission) fit quite well within that framework.
If Nolan erred anywhere in adapting the Batman character, that's where he did so most. Eliminating a major part of the character's most unique core psychological motivations.
I don't think Nolan erred as much as it is him experimenting with something new, to create a character arc with Batman. I agree with you in that Bruce Wayne isn't dead, but rather re-adjusted to make sense of the trauma around him.
And I don't think Nolan treated Bruce as if he died with his parents. By the conclusion of the Dark Knight Rises (and the Pit scene, as well as Bane's first fight with Batman), we see that Bruce has regained what he has lost, the will to live. And since he overcame the Pit, he now wants to live rather than die because he was unable to move on.