If that "something" is so visually interesting that it would be worthy of a photograph all by itself, otherwise it's just a habit.
Indeed, that is why I said "I have a habit". I catch myself doing it without thinking. In some cases i agree that this visually interesting thing is worthy of a picture all by itself but why not use it to help enhance a landscape? I feel that it helps add a little something to an otherwise boring composition is many cases.