So you feel bad about self-inserts, but you're fine with other people inserting you into canon, right? Like me, for instance?

As far as I can tell, they've got two choices; CRUSHING MISERY, in which case they may as well send Dean to Hell, or end on a nice defeating the worst of it and riding off into the sunset to fight smaller and less angst-inducing supernatural menaces. The fuzzy middle stuff (like Dean going to Hell, but Sam summoning him back as a demon who kills other demons), would be generally unsatisfying.