You're missing the point. Murdoch's getting a lot of criticism over fears he might "interfere" with the Wall Street Journal and presumably impair the objectivity of its news reporting.
So this is a very clever rejoinder. How can Murdoch's liberal critics complain if he does nothing more than Sulzberger does at the New York Times? After all, that would constitute an implicit criticism of Sulzberger and the NYT, which is blasphemous. So if Murdoch actually keeps this promise, liberals will have a hard time faulting him.
Of course the truth is that Sulzberger interferes all the time with the NYT and has further skewed its bias. So this promise gives Murdoch all the leeway he could ever want to do anything whatsoever he chooses with the Wall Street Journal. Later on, he just answers any complaints by pointing to even worse examples by Sulzberger.
Meanwhile, along with Sulzberger, Mark Haines of CNBC and John Harwood of the Journal, not exactly models of fair minded journalistic objectivity, must be passing bricks.
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