Maybe it's because UBISoft tried to be realistic in FC2 like having malaria and degrading weapons that will jam occasional. Most people didn't like these realistic elements and claimed that the game was rubbish or frustrating because of these elements. Even though i wouldn't mind some of the suggestions you mentioned the majority of game player do not seem to like too much realism in their games. The want to have that feeling of being invulnerable and over coming great odds. Not feeling of being "human" and "realistic" because that would just be too real and your character would of died from a single bullet wound just like in real life.