Sam was in the Cage with Lucifer. Imagine having him as your cell buddy. I felt so badly for Sam when "Lucifer" convinced him that he wasn't free on earth with Dean at all, but still trapped in the Cage. I loved Mark P.'s take on Lucifer and don't mind a "nightmare" visit from him to Sam from time to time. Real Luci is still in the Cage, so that story is done.
Also, I am sick and tired of Sam's story arcs being dropped for no reason on the show. I want them to squeeze as much sympathy and drama out of this situation for Sam as long as they possibly can. In other words, I don't want it cut short for stupid reasons or plot reasons like oh well, too late, let's move on to other things. That never happens with Dean but happens with Sam all too much. Not this time! This is a great avenue for character exploration for Sam and the brothers and I want it to stay, however the writers want to do it.
And I don't think Sam can be so incapacitated that he can't hunt. Sam was hunting in his "grapefruit" in the season finale, and he came out pretty well against Soulless Sam, as well as doing research and finding clues to the real world.