I don't do the Dead is Dead or Premdeath stuff, I like my role playing but I think that is just stupid IMHO specially if I have spent 40 hours in the game than i die, why the hell would i want to start all over again? I can understand why people WOULD but its not for me, if I die I normally just reload a save file and pretend it never happend, otherwise i could ask the people who are into the Dead is Dead kinda logic as Why do you choose to create a save file than for your character? I mean you are reloading the game up every time you turn if off so why not just make a new character every time you turn off the game? Its not like WE as people IRL can just "TURN OFF"
I think a better question would be why would the idea of somebody applying this rule would bother you so much. Some folks like to invest a great deal of time and thought into their character, while some other folks like to just turn on their console/PC and numb out for a few hours. To each their own, brohemoth.