In AC3, didn't Desmond and several other modern characters die? That seems like a good reason to flush the deadweight.
Well, it was only Desmond, and some Assassin-turned-Templar character that they introduced in 3.
There's a scene in a later game where a character is wounded but AFAIK they don't address that in the games again, maybe in some of the files you can explore in Origins or something but I don't recall reading about it, then again I played Origins a long time ago and then played through all the other ones :\
Could've sworn annoying British quip machine at some point, but maybe I'm just mixing fantasy with reality. Everyone else has gotten some decent lines so far, though. ---
Take me down from the ridge where the summer ends And watch the city spread out just like a jet's flame