I could be totally wrong.
But is there anything gamified that is
A) somthing meaningful and B) the participants aren't already invested in the idea of the meaningfulness of it.
I think I see gamifying almost on a par with a form of trickery for crap which isn't actually meaningful to begin with.
I do think you could probably make a strong case for stuff which is undoing a negative, like gamifying addiction recovery.
Again, I'm just pondering and but feeling