Not exactly a destiel piece, but it's not really not one either, so... Kind of just throwing it here since I don't know where else to throw it.
The apple pie life- it isn't all it's cracked up to be, Dean decides, but it's still light-years better than hunting. Even if hunting is something that's seeped into his bones, something he might even kind of be missing, he knows he can't go back. Not because of last minute promises to Sammy, but because he can't stand the ugly mugs of every other mangy hunter out there. What good had they been? What had any of those assholes actually done to help stop the apocalypse? Nothing, as far as Dean can see.
Why did it have to be the Winchesters that ended it? When did the big, cosmic joke become that they were in charge of protecting the Earth from all the plots conceived of Heaven, Hell, and whatever fell between? How did searching for their dad turn into preventing the end of days? What? Because some douche bag angels decided they wanted to wear the brothers to the prom? Or was it because the Winchesters had their own angel at their disposal? Not that he hadn't been basically out of commission half the time.
So fuck them. Let everyone else deal with whatever comes next; Dean is washing his hands of the whole thing. He's down a brother and a best friend, so the world can be down him. He stopped the fucking downfall of humanity. He deserves a fresh start.