its absolutely correct that the reason why we watch any serial or show may not resist itself as it tend to change the reason as the time passes
so as if we watch any show 4 a particular person ...we are made to watch all other actor and their performance as characters... so the taste may get changed but the base is same.........
if they show any particular actor alone in the whole episode... this is something unusual and unreal so watching others also shows their bond with each other so we get to know actors scope and their acting skills