I don't know much about tennis either and like you, felt, well not disappointed as such, but empty, that there wasn't anyone for me to support in the second week, treating it more like a 'world cup' match, and routing for the country rather than the person, when really I shouldn't have. Tim plays for himself, as do the other players, at these tournies, and just for their country in Davis Cup and Olympics. There are other players that I like to watch, it's just that I really like to support 'the home team' when I can.
Murray likes to think he plays for his country out there whether it be Davis Cup or ATP I think... Henman may of felt the same. You are naturally representing your country whether you want to or not