There is a self-reinforcing network of assumptions in that statement:

- Good architecture beats good code.

- There are things I can express in dynamic languages which are hard to express in static languages.

- If you're not expressing those things, typed static languages win.

- When you're contorting your architecture to fit into static languages, dynamic ones win.

- Of course, if you don't have experience with dynamic programming, you won't think to express certain things or structure code certain ways.

There are, of course, academic languages which do both well (including optional static type systems for Lisp), but I'm not aware of any in widespread industry use (with an ecoystem of libraries, documentation, etc.).