And lose literally his last place of refuge capable of withstanding U.S. demands in the world? If he pisses Russia off, he's either in a Russian jail (horrible) or in US hands (possibly equally horrible). Why do you want this? Has he not sacrificed enough of his life?

Almost everyone, Russians most of all, know that Russia conducts fearsome mass surveillance of its own population. It was Snowden's revelations about the capabilities and intentions of the U.S. that came as a big surprise to many, and so were most needed.