Well, the curse is not the actual threat. If's more a symptom of the threat. Acererak's plan is not just to bother the folks who've had the resources to be raised from the dead.
Sure, but as written, the "resurrected people are dying" is pretty much the whole hook of the plot. Stopping that is meant to be the main motivating factor for the players. As written, the rest of Acererak's scheme would not be clear until the adventure is 90-95% complete.
I don't mean to imply that this adventure is bad or broken or anything, but the book insists up front that the Death Curse is the centerpiece of the campaign (and the current AL season insists the same thing) and personally I find it super lame and awkward from the get-go.
ToA is redeemed by being filled with great locations and great characters and monsters. But its central hook irritates me.
I think the Chult that WoTC has given us for ToA is a great campaign setting. I'm not at all sure ToA is a great "adventure", though.
As a DM, I really enjoy coming up with fun ideas for my players. The tedious part for me would be the dirty work of structuring my stuff in a way that would be accessible for another DM to run, and make their life easier. WoTC apparently feels exactly the same way and that's why this book is a lot less user-friendly than it ought to be.