I remember this being asked in an interview around the time of release. The dev said something like "Sorry, this is a technical issue that can not be fixed". The game is probably hardcoded to fade out and remove corpses immediately after the death animation finishes or else someone would have found a line to tweak on the PC.
My guess this is an ugly solution to a problem that may have only been present in one or a few situations (perhaps not even on the PC version). Instead of fixing these situations, they just made it an engine-wide solution and have the bodies fade out quickly throughout the whole game. The game was delayed several times, no? I'm just speculating here.