Somewhere between what I intended to say and what you understood, something important got reversed. Possibly it was my poor choice of wording.

I mean dynamic the same way that you do, and what I was saying is that templates are an option on dynamically generated pages, but not on static ones. Therefore if you're developing a dynamic site, you have design options that you don't if you have a static one. Technically that is not entirely true (you can use templates in a "make"-like step with static sites - Template Toolkit has explicit support for this), but exceptions tend to be rare.