Why do the mil prosesmiths / propogandamills insist on "transfer case" instead of coffin?

An Army carry team carries a transfer case containing the remains of Capt. Joe Blow.
He died from an improvised explosive device while supporting Operation Enduring Freedom.

Should read:

Pallbearers carry a coffin with what's left of Capt Blow after he drove over a mine in the Long Futile Crusade