I haven't stopped caring. But a lot of things have gone on that's made me a little less interested in following it a rigorously. And to be perfectly honest, a lot of that comes down to Ward. To me he ruined the fluff of the various Astartes chapters so much that it was almost irreparable. But it's nothing on what he did to the Grey Knights. The Knights always used to be this awesome force, not a lot on them, but what little was known was epic. Then Ward comes along, and I don't know, he just seemed to make so many different aspects of them that they somehow ended up losing what made them so unique and bad ass. Then came fucking Draigo.
Other than that though, nothing seems to be happening. Sure the defence of Baal might turn up eventually. But honestly we know the result of that before it starts. There's not a chance in this world that GW would ever kill the Blood Angels off. So in the event they do progress that, expect a healthy amount of Deus Ex Machina to resolve the issue. I doubt they'd even kill off a major character like Dante or Mephiston. Hell they killed Tycho off and he still appears in every codex.
Another turning point for me, was when the 13th Black Crusade campaign didn't end the way they wanted it to, so they just retconned it instead. That really rubbed against me in a bad way.
But yeah, I still follow it, I still care. I'm just a little more jaded about it all since Ward and don't follow it quite so religiously as before.