Okay, so it took several weeks of postulating, lots of Tumblr scrolling, and a hefty amount of watching interviews with the cast and writers, but I think I've finally figured out why the second half/ending of Stranger Things season 5 flopped so hard for viewers while the writers seem very content/proud of what they've made.
My primary thesis hinges on the idea that to the Duffers, their characters are archetypes. Just archetypes. Will is the outcast, Mike is the storyteller, Lucas is the fighter, Dustin is the brain, and El is "the magic of childhood." And if you reduce these characters to that one core component, Season 1 and Season 5 vols. 2 and 3 tell a very cohesive story. Childhood ends, but the outcast finds acceptance, the brain gets research and relationship, the fighter gets to lay down his weapons and stay with his sweetheart, and the storyteller gets to keep telling stories.
Seems like a pretty perfect and predictable tale, no?
The problem is that after Season 1, these characters grew and weren't just their archetypes anymore. Will deeply engrains himself in the places where he isn't an outcast, becoming a peacemaker and a protector. Lucas explores his place in the world in relation to the ideas of race and popularity. Dustin's story is one based around emotion, exploring the intersection of friendship and grief. One of the most essential elements of Mike's growth is when he learns that he needs to stop telling himself stories about the people he loves. And El's exploration of childhood is far from magical; it is messy and broken and beautiful and everything that childhood should be.
And as we watched Season 2 through Season 5 vol. 1, we fell in love with the characters. Not their archetypes. We fell in love with their growth and their failures and every real, tangible moment, peppered with a delightful dose of nostalgic sci-fi horror.
So therefore as viewers, when we hit Season 5 vol. 2 (especially after "Sorcerer" was such a promising cliffhanger), we expected these characters to get conclusions that matched their story as people. What we got was a sudden and jarring reversion to archetypes given the pre-planned archetype endings.
Given how the Duffers talked about Season 5 in the interviews leading up to it's initial release, how they refer to the core characters, and especially how they have talked about always knowing what the end of the show would be, I don't think it's too far of a leap to theorize that they committed to an ending that suited characters who, in their minds, were still exactly the same as they were in Season 1. (I am also not above guessing how divorcegate may have played into the shift in writing between vols. 1 and 2.) But to the viewers, and I also think the actors, these characters had grown. So when they got simple conclusions, which would have been perfectly satisfying without ten years of storytelling in between, we were and still are upset about the amount of nuance that was abandoned and ignored.
I am very anti hating or bullying storytellers for telling the stories that they wanted to tell. I won't hate the Duffers for making the tv show they wanted to, and I think a lot of the aggression toward them and what interviews and documentaries have revealed about the making of Season 5 (all of which is pretty standard in the film industry) is very misplaced. This is just a suggestion that maybe this is the reason there was so much disconnect between them and the audience regarding the ending.
Maybe they had the whole story mapped from day one, and didn't change it over the course of ten years. Meanwhile, ten years was a long time for the characters to grow, for the actors to grow, and for us to grow. We wanted a story that reflected the nuance of the middle of the story, and we got very simple bookends.