I have a simple view as someone who signed more NSA disclosure agreements over my 20+ years than I could ever hope to count. This is very black and white. First, remember the guy was a grunt level worker without the education or experience to adequately judge the information to which he had access.. and from what I understand his access wasn't because he was working on the projects, but rather maintaining the systems that held the information. He was a young nobody who saw something and reacted most likely without much thought of the consequences. He also had multiple avenues to take his concerns, but instead he chose to commit treason.
What he did isn't about the bigger picture this has turned into. This is about an employee who signed disclosure national security agreements and subsequently stole NSA data and released at least some of it and sought asylum with the worst possible country he could choose. If you think the Russians gave him sanctuary out of the bottoms of their hearts then you're naive.
Snowden stole more classified data and has done more damage than any other 20 spies in our history. The only control we have for keeping our classified material classified.. is punishment for offences ranging from negligence to treason..
Again, it's not whether you think the material should have been made public, that's a decision made by the leaders YOU and I voted in as part of our representative republic.. we voted to give them both the authority and right to prosecute those who break their agreements.
Would so many people feel so good about this guy if he had a morale issue with.. say nuclear weapons, ship and submarine movements, or how about the SEC access codes?