Once they killed off Jade, I pretty much lost hope that they were going anywhere with the story (and they didn't). She was the only character in the game that was even remotely interesting, and instead of doing anything with her, they just said "Eh, fuck it." and killed her off. In fact, it seems like whenever a character gets introduced, they just get cast aside immediately, and nothing ever happens. It's a story where it seems like stuff is happening, or going to happen, but nothing is actually going on. And it all culminates into that last sequence which, I don't really need to say anything about it, you already expressed my feelings in your post.
It's fuckin' fun as shit to play, though.
I thought the best aspect was you being an undercover agent. I wish that would of been played up more instead of you going rogue and not really having much else to do with them. Most of the relationships with the survivors were much too forced imo. Especially with the kid (that dies of course). You have like two conversations with him and then your character is super broken up about him dying for some reason.
It's probably my GOTY so far and, yes, that part was terrible. Not just that... but I didn't understand until after about 10 deaths that I had no choice but to run for it. I was trying to sneak my way through that area. That and the QTE boss fight are the worst parts of the game. Other than that it was extremely fun and I've still been starting it up and doing side mission on occasion.
Double handed the axe the entire game until I got the Scythe. The heavy attack on the axe where you spin twice... nothing topped that. So much range since you spin twice plus you swing in every direction. I'm always surprised seeing people playing because it seemed I was the only one that used it while everyone else used the cleaver. I never had any need for guns because of the axe.