Robert Comsol wrote:
It might have served some "See what you have done, now we all pay the price for your negligence" context in the film.
It plays to me like this was sorta Scotty's point to Kirk. That said, Scotty knows what it's like to sit in the big chair, and I don't think he would blame Kirk for everything that happened; Khan had gotten the better of Kirk, pure and simple. In that sense, Scotty's really reminding Kirk of the price of everything that's happening, I think.
Also, the scene makes sense to me only if Scotty already knows that Peter's wounds are surely fatal.
Not to mention, no doubt Scotty was just really grief stricken, and in shock, as others have said.