Alan Williamson, writing for Nightmare Mode:
Games need to treat death not as a fail state or a temporary roadblock, but as genuine loss, because that’s what gives the player a reason to live.
Skyrim allows companion characters to die in the course of the godlike Dohakiin’s adventures, and all the mechanic managed to do for me is discourage ever playing with a companion character. They are weak, die quickly, and die permanently. I would have loved to become attached to even one of these characters, but they ended up as just another rag-doll on the corpse pile.
Games that treat death with some gravitas have to balance loss with attachment and significant mechanics to allow the player to protect their virtual comrades. Otherwise, they become nuisances rather than emotional connections.
One example where permanent death of a companion is executed better, comes at the end of Mass Effect 2. In the final mission, the player is forced to assign the supporting characters to dangerous tasks which can end in their permanent deaths. However, the choice is made more difficult by the threat that choosing the wrong person for the job could endanger the success of the overall mission. In this particular situation, I intended to sacrifice no less than three characters (all of whom were added to the cast in the second game) in order to guarantee the safety of two from the original game.
When I lost only one supporting character, I was pleasantly surprised, but in a cutscene close-call, I worried that by actively protecting my treasured teammates, They would be cruelly taken away at a moment beyond my control. Happily, they were not. But the loss of that one character, in spite of my having specifically chosen him for the chopping block, affected me greatly. I felt guilty and in some ways coldly calculating in my choice to sacrifice him.
So what is the difference between the two? In Skyrim there is rarely enough time to build an emotional connection with a companion because of how easily they can die in the process of simply playing the game as it was intended. In Mass Effect 2, the relationship between player and supporting characters builds over the course of the game (sometimes multiple games) while the player and his or her friends are essentially invincible. It is only after this incubation period that the character’s death can take on any significant meaning.