Cameron reasoned that he doesn't need any more Academy Awards and that an award for Bigelow would "finally" recognize her for the "scope of her talent."

Read the transcript from Charlie Rose's interview with Cameron:
Charlie Rose:
What do you make of this competition between you and Kathryn Bigelow? Two very different people who married. But more than that, two people who share this sense of wanting to be good filmmakers.
James Cameron:
Yeah, I think we're really not that different in so many ways, and we know that about each other, that we're both dedicated to the craft. And for both of us, it's very much about the work and about a total, consuming passion for filmmaking. And you know, I think that's what drew us together, is each respected the other's passion and craft and so on, plus she was gorgeous.
Charlie Rose:
Is gorgeous.
James Cameron:
Yeah. You know, but in our minds, it's not a competition. That's a narrative that's imposed by others, because it's, you know, it makes a good story. We're so celebratory of each other's work, and we've remained -- you know, I produced two of her films, one of which I produced -- wrote and produced -- wrote it with Jay Cocks -- after we were divorced. So, we've worked together, and we've been supportive colleagues. She saw "Avatar" five times at different stages of its development, from very crude --
Charlie Rose:
You mean you would go show it to her and say tell me what you think.
James Cameron:
Yeah. She's come over -- and tirelessly come over, watch the film. This is over a period of six or eight months and give me notes and even Mark Boal, who wrote "The Hurt Locker," came and gave me very good notes, very helpful notes. And they had shared Hurt Locker with me earlier on.
Charlie Rose:
Right.
James Cameron:
And my note was very simple. Don't change a damn thing. You know, because they showed it to me fairly late in the process because I had been shooting. And I said, don't change a damn thing. This thing is great. And they were, of course, very nervous --
Charlie Rose:
Why is it so great, do you think?
James Cameron:
I think just because it's consummately good filmmaking -- excuse me, consummately good filmmaking. I mean, you are in those guys' shoes, and you're there. I mean, I have been at screenings and watched people literally sit on the edge of their seat, literally. I mean, you hear that expression all the time. Literally sit forward for the entire movie, hand clinched like this. It's that tight. It's that taught, you know. And for her to -- I mean, she's outgunned the guys, you know, definitely. And of course, her --
Charlie Rose:
You're not surprised by that.
James Cameron:
Not at all, not at all because she's always done that. But it's the recognition, you know, finally the recognition catching up with the scope of her talent.
Charlie Rose:
So if someone sitting there says, look, I'm going to give it to Cameron, best picture but Bigelow best director --
James Cameron:
That would be a fantasy. That would be my fantasy outcome, absolutely.
Charlie Rose:
That would be what you'd like to see?
James Cameron:
That's the best possible outcome because it's -- because I know how hard my team worked and how much they would -- how proud they would be of that accolade, you know what I mean? And look, for myself, I have already got an Oscar. I've got a couple of them, you know. And I respect the whole institution of the Academy Awards because it's so -- it's the pinnacle of achievement in my chosen profession. But I don't really need another one. But to be honored -- you know, to have the team honored and for their accomplishment, that would mean so much to them. And I think that would be the fantasy outcome in all of this.
Charlie Rose:
So you're saying to the voters, please take a look at my team and go for us as best picture. But --
James Cameron:
Yeah, and I --
Charlie Rose:
-- go for Kathryn Bigelow for best director.
James Cameron:
I mean, all I can say is that that would make me very happy if that -- you know, I don't want to try to get --
Charlie Rose:
Happier than if it was best director for James Cameron?
James Cameron:
Honestly, yes.
Charlie Rose:
I believe you.
James Cameron:
Absolutely.
Charlie Rose:
I believe you.
James Cameron:
Absolutely. I mean, I just think she's worked so hard for so long. And there's something very irresistible about the idea of a woman finally being anointed in that role. It's ridiculously long overdue. And she, of course, would reject that being a woman should have anything to do with it.

source: huffingtonpost