Here is a thing that the SPN -in text- does sooooo well and soooo often. It takes a characters, and it throws everything at them until they bite at their own SELFISH dream. Once the character lets their own personal light shine on their face, once they see their preferred extra-special-just-for-me-future, it snatches it away and asks:
“What now? How will YOU respond? How will your LOVED ones support you? (WILL they? CAN they?)"
That's what happens to the in-text Dean character when Cas dies, and especially when Cas perma-dies. He has become an integral part of Dean's future. In-text Dean is always trying to figure out why Cas is different. Cas becomes the future that Dean sees for himself, in one way or another... faith in a better tomorrow, as Mia says, in all the ways.
And the tragic thing is that despite being such an open character, a heart-and-love-character, Dean was on the whole such a skittish character. He falls for things, sure (everyone does), but he didn't as a broad trend tend to fall for things the way that Mary and Sam did. (And Mary and Sam tended to be bright-eyes runaways who originally grasped more eagerly for their own happiness's.) They also seem to get more easily recruited (BMoL).
This is the axis on which SPN turns. Find the secret future. Kill it.
It turns in smaller, less torture-nexus way in SPNwin, and I was thinking about Jericho today, cause i was reading a fic about music and musicians, and like... In the Hang Onto Your Life episode of The Winchesters, Jericho, the musician, the musician who saw his future playing music, perma-injured his hands. That's no small thing! It's a huge, life-altering, disability-and-future thing!!!!
But it's the same thing, writ in miniature.
It follows the long line of SPN, getting people to bite the bait of their future, and snatching it away. It's the “everything we've always wanted" of it all.
And like I said in above, it's about recognizing John in everyone, sure, and acknowledging his harm, sure. But there is no THE John. You're not going to “solve" SPN with a game of “who's the John." John is a man incapable of grieving and being there for his family, but specially he struggles in the context of abandonment and lies, and that's no small thing, even if it had very big and cruel consequences for all involved.
