To hear Dawkins' talk, it sounds as if he's refusing to debate Craig because he holds an evil position, on killing the Canaanites.
But the fact is in Dawkins' universe, statements like "It was wrong of the ancient Hebrews to kill all those Canaanites and Amalekites" is neither true nor false. He may dislike it pretty intensely, and no doubt he thinks it conflicts with some strong moral intuitions that he has, but his philosophy doesn't even allow him to charge Craig with error on this point.
It isn't that Craig holds such a preposterous position that this proves his total irrationality. In fact, he holds a view that Dawkins himself would not consider to be false, let alone refutable.
Somewhere in England, an emperor is missing his lab coat.