Manning was not a good candidate for martyrdom anyways. His case had obvious ulterior motives, he didn't turn himself in (but did brag about it), made the bares

Manning was not a good candidate for martyrdom anyways. His case had obvious ulterior motives, he didn't turn himself in (but did brag about it), made the barest of attempts to go to the media, leaked way, way more than was necessary, what he did leak wasn't even as bad as things like Abu Ghraib or the Mahmudiyah rape/killings in Iraq (which came out via normal whistleblower channels, btw), leaked things in a way to put Afghani informants and sympathizers at bodily risk, I could probably go on. I mean, there's a reason Snowden sought to differentiate his methods from Manning's, even if he had the same overall goal.