At VERY first, I also thought the finale was a bit underwhelming, but then I thought about it for 5 seconds, and... you know what? I think it was actually very fulfilling.
First of all, they ended the Andrea arc. Andrea basically had a STORY, starting with Amy's death. She became depressed and despondent (trying to stay at the CDC and leading Dale to believe she was dangerous to herself); then she became hardened and started thinking in s brutal kill-and-don't-think-about-it mentality (Her relationship with Shane, shooting Darryl by accident, her general awful attitude towards everyone when asked to do anything helpful around the farm, letting Beth try to kill herself); then, with Dale's death, she became overly sympathetic and never wanted to see anyone die again, and that led her to making some truly awful decisions this season with the Governor and the false "promise" of Woodbury. And finally, in the last three episodes, her blinders came off, and she tried to make the right decisions. But it was too late. Still, her character progressed, and she had a fully developed story arc.
Secondly, they resolved Tyrese's problems with the prison and Woodbury. While not a MAJOR plot point, they'd been setting it up for 8 episodes or so (since the midseason finale). Tyrese finally saw the Governor for what he was, and Rick got to make up for chasing his group off.
Next, they destroyed the Governor. No, they didn't KILL him, but--just like how Governor had started killing people and letting them turn rather than headshotting them out of mercy--they did something worse; they took everything from him. He lost Woodbury, he lost his people, and he lost his pride. He ended up having to run away in anger and frustration, with only a truck and two of his followers, neither of whom seem particularly loyal to him any longer. So they resolved that ARC, all the while keeping the Governor alive as a possible threat next season or further off, which I actually think is kind of genius.
And finally, with Rick bringing the people of Woodbury to the prison, they resolved Rick's collapse this season. He went from being a good man to a man who was teetering on the edge, both morally and psychologically. His rebuilding that started in the episode with Morgan is complete. He's clawed his way back to stability. he refused to give up Michonne, he gave the group their voice back, AND he stopped chasing people away by doing the exact opposite and letting people in. He's back to being the altruistic, if flawed, hero he set out to be when he first appeared in Atlanta.
And it still managed to set up a future plotline--what the hell is going on with Carl? Carl is starting to take a very Shane/Governor point of view right when his father has come face-to-face with the fact that you can't really live with that stance. Sure, you might SURVIVE, but... will you be LIVING? So what is going to come of Carl? Is he becoming, in a way, a future threat to the group? Is he just struggling like Rick did, and will eventually come over like his father? Or will his immaturity and youthful anger take him further than Rick went?
So, really, to me? When you look at what all the finale DID achieve, it seems cheap to say "nothing happened". Sometimes a good finale ends with more subtlety than the nuclear warhead everyone expected.
And I dug it.
