I've only just gotten around to watching Saturday's ninth season finale of Doctor Who and it was exactly what I expected it to be: a rebooting of the status quo, a wiping clean of the slate, undoing the the character work of the season to allow the show to proceed fresh and unhindered. This is what the show is, and it's time fans came to terms with that.
Doctor Who is a show trapped between between showrunner Steven Moffat's love for what the show is at its core--a show about a wacky time traveler who goes on zany adventures through all of time and space with his friends--and that Moffat considers it the Greatest Show of All Time. Moffat's love for Doctor Who means that every main arc under his tenure has been a celebration of the Doctor. All you need do is look back on Matt Smith's tenure to see that the Doctor was a relative messiah, his name being the only thing necessary at times to avert crisis and make his enemies run in fear. Moffat is the ultimate fanboy, and he's in a position to indulge in that all the time.
The stakes of the show's main arc must get higher and higher each year to live up to Moffat's lofty ideals of what the show and its titular hero are. There will always be a Huge Thing That Happens (this year's convolution including an elaborate trap by the Time Lords that once again allows the Doctor to Teach the Universe a Lesson), but ultimately nothing can ever change because the show also has to remain what it is. The secondary problem is that what the show also is at its heart, what it began as, was a show to awe and frighten children. Moffat's lofty expectations for the show (it's a global phenomenon at this point) include broadening the audience-- to adults (I'm 26) and maybe even fans of the show's original run (like himself). For that audience, the show has to mature a bit as well, which can explain its tonal shift at times toward the darker, and its flirtation with ideas of Death and consequences and such. But those ideas don't stick around long, do they? There's always a fix. After all, what kind of children's show allows for consequences for its main character?
So what you get is a show that parades an All-Important finale with a Reckoning for the Doctor, only to pull the rug out from beneath you. The Doctor is the one immutable truth of the universe and has to be allowed to run about in his Blue Box.
What I've learned to do is just not stand on the rug.
I watch the premiere and the finale of each season just to get a sense of the season's tone and status quo. For me then, the real season begins once the episodes become less connected. Would you agree that, with that in mind, this has been one of the finest seasons in a while? It's probably no coincidence that Moffat wrote few (if any) of those episodes. Those were pure adventure episodes, pure mystery episodes--and they were all thrilling. No talk of the Mythology of the Doctor--Clara even functioned as an indispensable humbling force for the Doctor--and all allusions to the show's main mystery were shoehorned in and therefore easily ignored.
To speak more specifically about this finale, however: its worst crime is the cheapening of Clara's death. Her decision to face the raven was just that: her decision. It was her moment and it had true consequences for the Doctor. It's something they show has touched on before (and it's something the show would keep if it were the kind of show with an endgame in mind, not just planning indefinitely). The Doctor inspires people to do things that could, and probably will, get them killed. The Doctor has to live with that.
...Except when he doesn't. He goes back in time and fixes it so that Clara's death has his permission. He allows himself to be punished for it despite Clara's wishes, and especially so now because he is now actively complicit in the erasure of her existence. The Doctor can't accept that Clara was inspired by his example (she is very much like him, as this episode makes explicit), and that inspiration cost her her life, so he has to erase responsibility. He and Clara "flip a coin" and allow the consequences to fall as they may. No culpability, no muss, no fuss.
This would be compelling as a character flaw, but it isn't. The show lauds it, and erases the Doctor's mind so that what he's learned is gone, and he can go off in his TARDIS again. Ideally this comes back to bite him in the ass but... I'm not holding my breath.
The consolation prize is that Clara and Arya Stark get to run around space and time getting into their own wacky adventures with their own TARDIS. But if you want a show with two female leads, it can only exist in an alternate universe and in your imagination. Never mind the fact that they're flying around in a diner, a place where they literally work to serve--I don't care that it was the same diner from a previous finale. Why that diner? The Doctor points it out himself: Clara wasn't there.
Furthermore, you're going to tell me he flat-out ignored the painting on the door of the TARDIS of the girl he just spoke to that literally dematerialized to the sounds of a TARDIS taking off? The only logical conclusion the Doctor can make from that was that that was Clara, in a TARDIS, and now he has to go chase after her. Isn't he "clever"?
Unless, of course, Clara's final words to him allowed him to say to himself, "Eh. She's gone. Ignore it and move on."
But that's what the show did, didn't it? It referenced itself ("Run you clever boy...") and gave the Doctor his coat back and a new screwdriver (honestly with the redesigning of the screwdriver), so everything is new and over. The Doctor doesn't remember Clara, so... let's move on. Let's go galavant about with River Song (Sigh).
The episode started in an "epic" way because that's how Moffat constructed it. Have you ever noticed how his finales begin quietly? With a mystery or any other framing device that slows things down? It's because he's distancing himself from the rest of the season to tell his own story, only paying lip-service to everything else that has happened, while subverting and reinventing the status quo of the season for his own purposes--which are typically that the Doctor is the Best and this show is the Best and it will be allowed to do this thing regardless of anything else.
Let's assume all of that's okay. Let's assume it's okay that the season builds to this big mystery that the Doctor solves or a Big Bad that the Doctor outsmarts because he is the Doctor. Even with that assumption, the finale doesn't work because it commits a fundamental sin of storytelling: it tells us rather than shows us. The reveal of the Hybrid, the main mystery of the season, happened while the Doctor and Arya Stark were sitting down and talking. The reveal is that the Hybrid was him and Clara the whole time. That's Moffat's calling card, isn't it? That so and so or such and such was the thing the whole time. That the mystery folds back on itself to once again say that the thing everyone feared, the thing that was the threat or savior of the Universe, was the Doctor.
Again. Remember the prisoner in the box? "Don't open the box! He'll destroy the Universe!" It was the Doctor, and he put himself in there because he's so very clever!
That's why I've grown to tune out anything related to the season's main arc or its mythology--because it's all going to be the same: the Doctor is Important and his friends will commit themselves wholesale to his Importance but nothing will change because the Doctor has to remain Important.
That isn't to say there weren't things to like about the finale--there were, but those are different for everyone, and are probably tied to the performances and recurring images and songs on the show. What I will say is a final "bravo!" to Jenna Coleman. She went out with her finest performances of the series, and it was a great pleasure to watch her, and to watch her lift Peter Capaldi to new heights as the Doctor.
Ultimately, though, the audience is the Doctor's main companion: going on crazy adventures throughout the year only to forget them all and do it all over again. If only the show would embrace that and stop trying to convince us otherwise.