Let me rephrase. Dynamic languages aren't conductive to a subset of re-factoring - the cases which involve renaming identifiers or changing types throughout the project.
They invented those too. Indeed they're listed at the link I provided.
It seems strange to argue that what gave rise to a thing isn't "conducive" to it. Actually, it's more than strange, it's a contradiction in terms: http://dictionary.reference.com/browse/conducive.