They are hardly straw men. No one is dismissing natural selection as the agent of change.
Natural selection is a different issue from how the morphological change occurs.
It is true that the evolutionists and Darwin, in particular, held to a view that morphological change was carried out by a smooth morphing of form. This is similar to what political ads do to a picture of their opponent. The frame by frame transform the man into a donkey or something else. But this is not what modern genetics is learning about how change occurs. If genetic programs were beanbags of independent genes,each responsible for building a single part of the body, then evolution would have to occur slowly and sequentially as thousands of parts achieved their independent modifications.