I'm not sure why he is so certain that Mr Vallely has not examined the creationist explanation. The problem is that, though it could be true, it is not a scientific explanation. That is to say, it is not an explanation that generates testable hypotheses.
The theory of evolution and natural selection has generated enough hypotheses to keep thousands of scientists occupied all their lives in exploring them: from the search for order in a fragmented fossil record to the conditions under which altruistic behaviour might be expected to emerge from the selfish interactions of genes. Even if it turned out not to be true (although the evidence is so far overwelmingly in favour) it would still have been the most valuable scientific hypothesis that man has yet produced, because of the huge expansion in our understanding of the natural world that has resulted.
What does the creationist hypothesis do for science? It answers every question of "why?" with "God made it that way". There is nothing for science to do if any explanation in terms of complex interactions of structures and forces could be undermined by a miracle. If God could create the world, and trivially keep animals alive on an ark, then what's the point in researching cancer? It must be even more trivial for him to start or stop the reproduction of malignant cells.
Far from being common sense, for the scientist, creationism is a counsel of despair.