Same, there is a feeling, I think, that his motivations weren't particularly brave or pure, and that he hadn't really exhausted legitimate channels first. I'm glad the excesses are coming to light, but his flight, justified by fairly over the top claims of fear of torture and assassination, all couple to other things making him seem less a whistle blower and more anti-American. As soon as he was a international celebrity his most ethical choice would have been to come home and face the music, torture and assassination obviously being off the table at that point, though I don't think they ever were.
The most anti-American thing to do would be want to send him to prison. Especially given the inhumane treatment that Bradley Manning has faced.