Outing himself so publicly was one of the worst things Snowden could have done. Doing so before he was already in a country which had guaranteed him political asylum was just idiotic.

A leak like that one really didn't need the figure-head that the identity of the leaker would provide, and given who he was angering it was only going to make his life painful.

A good leak through the right channels doesn't need to be backed by anything. All it needs to do is get the right questions asked to the right people, publicly. If the outlet the leak comes through is trusted enough, it doesn't need the figure head, and it certainly doesn't need a figurehead holed up in an airport in Russia.