A few years ago, The Saturday Times featured a very interesting article explaining why people care so much about stars they have only met on TV.
The theory states that it comes down to a wiring in our brain that originated at a time when our ancestors were hunters gatherers. In those times someone who was in your immediate surrounding everyday, someone you saw everyday, had an importance in your life, be it a relative, the leader of the group or your mate. In other words, there was a direct relation between the number of times you saw a face and the importance the person in question had in your life in terms of survival or in terms of authority and hence the attention you had to give to that person.
The same kind of phenomenon can still be observed in babies who smile when they recognise the face of their mother. It can also explain the importance of pictures, photos and imageries in our life. Ever wondered why you keep a picture of your loved one in your wallet? or on your desk? Isn't it an intuitive way to counter the slow natural decay of our feelings when the person is not physically close to us?
Today, in the age of remote viewing, this wiring is no longer so relevant but still influences strongly our behaviour. That is why people do care about persons (and that covers movie stars as well as politicians...) they see every day of their lives but who do not have any kind of impact on them otherwise. This unique feature is key in the manipulation of the masses.