Changing Quality of Literature

Several times in the past weeks' classes, someone or other has brought up Beowulf as an example of something which was literature by the standards of the past, and continues to be literature only because of Steker's third point (that something which was considered literature by the standards of its day will continue to be literature despite the existence of different standards).  I would not agree with this view, as I think that Beowulf still meets the qualifications to be literature, even if those qualifications are different in modern times as opposed to when the tale was written.  In fact, I cannot think of even one instance wherein a work which was considered literature would not be considered as such if it were written now.  Beowulf, and many other ancient works of literature, would likely be considered bad literature if they were written now, certainly; but they would still be literature.