With those shooters you mentioned, I think that's because of the focus on competitive multiplayer. People buying those games just for that. With Destiny, and this is all subjective obviously, but from what I've read from some on GAF and from what I've heard from people I know who have bought Destiny, the PVP suite isn't nearly substantial enough to make up for the lackluster and repetitive solo experience / storyStill don't see why people care about the story. Do you buy cod for the magnificent story, or battlefield etc. Nobody cares about story in multiplayer online shooters.
People don't even follow the story in MMOs.
There's also Bungie's history with Halo to consider. Not that Halo is in any way genius storytelling, but the universe and lore was pretty damn interesting I think. It had memorable characters, enemies, and some pretty epic setpieces throughout that original trilogy (ODST also had a pretty good campaign). By comparison, Destiny seems really disappointing with its lack of ability to draw you into its world and its boring mission design.
And you could say part of that is because Bungie didn't set out to make a single-player shooter like Halo, but I don't think they went far enough in the other direction to make up for that. Like I've said before, it just feels like a dull compromise between an MMO and a shooter.
Also, maybe I'm alone in this, but I definitely follow the story and the lore in MMO's. I don't lean on it as much as I would with a single-player game obviously, but it's still a major reason why I continue to play WoW 10 years after launch. I love learning about that world and the characters in it.