Andy Greenberg ponders it:
It could be argued that the Times wanted to focus on source material that it more actively obtained and that wasn’t shared with any other publications. But neither of those factors stopped the newspaper from submitting its historic reporting on 1971’s Pentagon Papers and winning a Pulitzer for that coverage in 1972: There, too, the material came from a single, willing source–Daniel Ellsberg–and was shared with many other media outlets.
The Times may instead be hoping to avoid owing any favors to a source with which it has feuded publicly. In December, the Times’ Keller told an audience at Harvard’s Nieman Journalism Lab that “”I don’t regard Julian Assange as a kindred spirit,” he said. “If he’s a journalist, he’s not the kind of journalist that I am.”
The Pulitzers are less, it seems to me, a true measure of quality. What they are is what most awards are: a reflection of a professional elite's view of who is respectable and who isn't. It's about reputation, and safety, not quality and risk. That also explains the NYT's decision to publish newspeak on the subject of US-authorized and implemented torture. They were worried about their reputation and source-greasing more than the, er, truth.
But for me, the power and punch of Wikileaks was not the curated massive doc dump the NYT did. It's the constant reference to a Wikileaks nugget in countless news stories since, especially in the Arab Spring. We simply understand the world – in all its hypocrisy, double standards and ugliness – more profoundly than we did pre-Assange. And we can better assess the real world trade-offs that our political masters would prefer to understand and make in seclusion.
Last time I checked, that was called democracy. And newspapers were for it.