I think it depends on your couch/sofa/recliner. when I lay down on mine, with my head on the armrest, I'm in the perfect position to watch a TV that's placed over the fireplace. I'd say that's why so many people put their furniture perpendicular to the TV, but it's more likely they think that arrangement is keeping the focus off the TV -- despite the huge monstrosity on the wall over there overshadowing any other decor in the room.