It is more like neighbours living in an apartment in happy harmony and one day someone decides to set fire to the building. Some neighbour thinks it's nice and warm, not caring at all if the other ones living in the apartment is choking and getting burned.
Not even remotely the same. My story choices are not affecting your story at all, they do not spread to your story.
I can easily prove it, I am going to load up the game right now and click on a bunch of choices and I can promise your game didn't change at all. Let me know if I was wrong and you noticed something in your games.
