I think the main difference is with a PC game you are playing the exact same thing; give or take, some games mix it up a bit with each play through but not much. Re-doing the same thing is really dull. Whereas with a DnD game with a death, and by this I mean
TPK, which is the equiv to character death in a SP game, we always start something almost entirely new...i.e. we go on to a new 'game': in a comp game analogy we dump Dead Space (I was getting bored of all those corridors anyway) and start playing Fallout 3!
With a single player dying then PC games do it in the same way. I played Left 4 Dead last night with 4 player co-op. When one of the 'PCs' died we rescued him later...he showed up as a 'rescue survivor'. Admittedly it was the exact same guy who got slotted a few minutes ago and in DnD that would only happen with a bit of magic instead of a new PC entire