So, I finally got around to finishing Dark Souls II (after getting sidetracked into cracking open a hundred or so Havel cans with the Malformed Skull in Belfry Sol), so I guess I can finally talk about it.
I think the big problem with the Dark Souls II narrative - as opposed to Dark Souls - is that it isn't all that well integrated with the game world. This is mainly because the game world itself isn't as interestingly put together. It's larger than that of the first Dark Souls, and technically involves greater freedom, but it lacks this kind of gradually revealed semantic coherence that the first Dark Souls had all over it. Ironically, the game improves massively once you reach Drangleic Castle, at which point the game becomes largely linear, but all the places are also more interesting in terms of narrative, difficulty and aesthetics.
There's a name for the way the first Dark Souls is put together, and it's "Metroidvania". Dark Souls II is more of an open world thing, and it doesn't work as well. What Dark Souls II lacks are tough mechanical limiters for the player's progress that you can overcome with exploration and strategy. The world of the first Dark Souls had more substantial difficulty jumps, between areas and a clearer sense of different equipment, strategies and such opening up new areas or giving you reasons to revisit old ones. This is what gives the game its structure. For instance, the Belfry Gargoyles are much easier once you find a smith to make you a decent weapon, while the fuckin' Capra Demon is much easier if you've got the Elite Knight set from Darkroot Garden. Then, once you venture down into the Depths, there's a good chance you'll get Cursed and suddenly you have a good reason to visit New Londo - you don't have to, but now you have a reason. Meanwhile, in the Undead Parish Andre will tell you that people go into the Darkroot Garden to seek the smith who makes divine weapons to help them in the Catacombs, which is a really nice hint; in the Catacombs, on the other hand, you'll find the Rite of Kindling, which is gamebreakingly awesome.
Basically, Dark Souls was more linear than the second game, but progress through the game actually feels more player-driven than DSII, precisely because it has better rewards for thoughtful exploration and a good sense that trying to understand how the world is put together actually helps you progress. The thing is, not only does this make the game itself more fun and rewarding, but in terms of narrative, it gives the game a lot of context and gives everything you do a particular sense of importance. That's what Dark Souls II lacks in the first half. You're told to go off to kill the Four Old Ones, but you learn a whole lot of nothing about them, and you gain nothing substantial, mechanically speaking, from doing so. The NPCs you meet mostly have no interest in them - not even Benhart and Lucatiel, who should be your peers. Shalquoir does tell you some things about them, but bizarrely, only after you're done killing them. Mostly, the NPCs tell you about themselves, not the world you're in.
In comparison, the NPCs in Dark Souls don't have more dialogue or anything, but they have more substantial goals, more interesting insights and more useful advice, all of which makes the world feel more coherent. The Catacombs feel like an important place because Reah and Petrus (and by extension, the entire Way of White) are invested in it, and Sen's Fortress and Anor Londo are made that much more epic because the likes of Siegmeyer, Solaire, Big Hat Logan and Lautrec are also on their way there. Kingseeker Frampt finally tells you clearly what's going on, but even without him, the presence of the other NPCs is enough to give the sense that there's a grand quest going on. The first game does lose steam after Anor Londo specifically because that was the high point of the quest, but then, you can't really blame the game that there's no way to top beating Ornstein and Smough and stepping into Gwynevere's chamber, because it's an astonishing climax and nothing in Dark Souls II comes even close. And even then, Oolacile is almost as epic as Anor Londo is, because the way it's embedded in the narrative is exciting and the boss fights with Artorias, Kalameet and Manus are dramatic enough to feel like you're fighting legendary heroes and monsters.
All that said, the problem with Dark Souls II may not be the lore. It's got a lot of interesting elements, nice ambiguities, subtle and less subtle links to the first game, and I'm sure that the theorycrafters will come up with a ton of interesting details in the world that will give a lot of meaning even to the boring early areas of the game. The problem is, the events of the actual game simply aren't as interesting as those in Dark Souls, because ultimately the way it's put together isn't as compelling, and as a result, it doesn't feel like the gloomy, yet epic quest that the first game was.