Not to defend such a couple, but rather myself, there is a certain value in the shared experience of television watching. Some of the best discussions my wife and I have had occurred after a TV show was over and we were discussing it (we still fondly remember our debates over how psychic paper, from Doctor Who, works).
Additionally, when we were first married, having dated long distance, we spent a notable amount of time sharing favored tv shows or movies with each other, the sort that we grew up with. There is something terribly nice about sharing a favorite this or that with a loved one, even if during the sharing there is little communication.
Of course, like most things, it does prove to have ill effects when done in excess.