Perhaps he looked at the results of other recent whistleblowers "doing the right thing" and realized that releasing information without the right choreography would end in no attention from the media or public about the issue and a ton of trouble for himself?
In an ideal world, he could release the information and each individual would engage with it, analyze it, make determinations about it, and judge whether or not it is important.
In our world, if he had followed the path of previous whistleblowers and given the information to a newspaper and returned to his house in Hawaii, he likely would have been immediately arrested, and the newspaper would have published very limited yet broad information in a single article in a way that would be easy for the rest of the media to dismiss. Then the character attacks would have overwhelmed the story.
Like it or not, presentation is important. Snowden has claimed his objective is making sure people know about these programs so they can decide about them. That objective, and his path thus far, seems perfectly in line with American idealism.