Corpses will decay after a bit. There's also a use for them in Poobah's game plots. (Hint: they're edible. Ewwwwwww!) So there's not really a *need* to bury them, other than keeping the world more immediately tidy.
Does this address your issue? If not, let me know!
So you're looking for sort of a way to *hide* things by burying them? That's pretty interesting. Maybe only those with special tracking skills could find them: the search for buried treasure. Thanks for the suggestion!
Re corpses and disgust and stuff -- I don't want to give away Poobah's intentions, so I'll just shut up now.