It's no one's fault but TED's, because they get to pick and choose who speaks. Reddit's admins don't have this privilege, and MK and the others don't really either. The admins have influence, but they don't have complete control. TED caved to greed (i.e. page views), and I have nothing but contempt for them. I sympathize with Reddit's decay, and I will for hubski if that happens, but not for TED, because they brought it on themselves. There's no good reason it should have happened, or should be happening, to TED.
This originally happened at TEDx which are local events put on by local groups, again reflecting a democratic sense of content creation. TED had the choice of how to highlight the video, but I'm guessing that it probably already was getting a lot of views before they even started to highlight it.