Yes, he revealed some shady intelligence gathering programs the US was running against its own people, but he also went out of his way to dump information on programs we were running against foreign entities. Had he stuck to the former, I'd consider him a hero and would support a full pardon.
But, when you run off to our biggest political rivals and tell the world the details of how we spy, you're violating the whistleblower's code of ethics to minimize injury. And, for what purpose did it serve? It did nothing to help the American people.
Without proving with certainty with no possibility of doubt that he could massively hurt the US government, he would have been a dead man. Releasing that information HAD to be done to PROVE he could hurt the administration.
You are completely stupid if you believe otherwise. He would have simply been killed before the media decided what to do with the data.
Remember, this is the Obama administration that has no problem missile striking US citizens who happen to be accused of being terrorists in foreign countries without even a sham trial. (Some of them are, but some of them might not have been before they were blown up.)
If anything, releasing that information made it clear he does want to help. Doing so put him at greater risk of ending up in jail assuming the US didn't outright kill him, because that's less excusable during a trial. It was the ONLY gambit that he could play to get the information out.
So the fault of the information being out there is twofold: the US for doing the illegal and morally wrong shit in the first place, and the US for being corrupt enough that whistleblowers get treated poorly (if not killed) in the first place.
That someone would come along and do this was basically a certainty.
And when they did, that they would also take and prove they have massively damaging information is ALSO a certainty.