Manning is not facing the death penalty, is not a "whistleblower" by any reasonable stretch of the term (except perhaps by lucky accident), and his actions were different from Snowden's, at Snowden's own admission.
Manning fits the definition of a whistleblower just fine, he brought a bunch of injustices to public attention.
As for not facing the death penalty, he looks like he's halfway at deaths door already, they're just taking their time about it. The world is watching the way Manning is treated and drawing its own conclusions from that.
And the U.S. undoubtedly killed a bunch of criminals by dropping the atomic bomb at Hiroshima, but even the most die-hard supporters of the bomb don't try to make that a positive point of the whole affair.
Instead that tends to be evaluated as a whole and not just with a narrow lens that happens to mesh with whatever you were looking to find.
