How would it harm the show if they were allowed to phone people, read books and watch TV? I never said anything about leaving, nice straw man.
Because then the whole show would be boring clips of phone conversations, watching TV, and reading books. You have to admit, it is a lot more entertaining to see them interact with each other rather than keep to themselves and watch tv/read books. They've got plenty of stuff to do at the house, play pool, play basketball, go swimming, diving, etc.