None of those three (bless their hearts) were anywhere near as effective in getting their message to the public as Snowden.
No doubt, but that's also why the concern that he may be turning himself from 'effective' to 'ineffectual' is so much greater.
I guess the simplest way I can put it is - I wish he'd stop taking his cues from journalists, however high-minded and well-intentioned and start working with a local lawyer specializing in human rights and civil liberties issues, yesterday.
Or, say, here's a take by Slate's resident libertarian: http://www.slate.com/blogs/weigel/2013/06/17/snowden_veers_i...
When your natural support constituency starts saying things like that you have a serious (and, inexplicably, self-created) image problem. I believe this is an actual thing rather than, you know, you and me just shooting the shit on a nerd message board.