It was a fine movie that hasn't been matched since. River of Souls and Thirdspace were both boring. Both writers and fans have consistently voted Walter M. Miller Jr.'s A Canticle for Leibowitz among the best works of science fiction of all time. Religion and faith, although not necessarily pro-organized Christianity, form the core of James Morrow's work. Different fictions have different central concerns.
Nobody has to like each work.
However, Mr. Allen's condemnation of an entire set of fictional tropes on the basis of some obviously unresearched and unsupportable assumptions sounds a lot more like the political ideology of 1930s British Communism than of anything resembling Christianity. I suggest he read The Sparrow by Mary Doria Russell, God's Fires by Patricia Anthony and Dark Debts by Karen Hall. Mr. Allen will find his reasoning severely challenged. He will find these three challenges superb reading in any genre he may choose to place them in. I have not yet read Legend , but I think I may soon.