How can it not be possible to provide a compelling subset of the existing use cases?
At any rate, you have a valid point that what we are arguing here is for a capability that has the potential of addressing a major class of problem that application developers face. Perhaps better than outlining the use cases individually might be describing the class of problems wakelocks let you address. I think Paul McKenney actually tried this a while back, but it rambled on too much -- but maybe John has the guts to run a more focused thread on the subject.
Alternatively, we could motivate the kernel community into appreciating that while they don't see the feature addressing their own use cases, a population of Android application developers are relying on the functionality, and it would be the responsible thing to either support them or convert them to use something else.