I have to disagree with that, with certain caveats. My experience has been that the players care very much about engaging their characters with the story -- BUT -- I consistently base my stories ON their characters and ideas. My home game is intensely collaborative, to the degree that I asked the players to help develop the people and places in the town.

I should probably amend the statement to: "If you're going to kill a character, make it meaningful to the player and/or the story."

RE social time - we build in some social time in each session for catching up, and we socialize a lot outside of the games. This probably contributes to more focus on the story/game when we play, as we have separate social time.