Respectfully, I think you are mistaken to say that Regan's speech did nothing. The reuse of Regan saying "tear down this wall" in various pieces of remix culture is evidence of the iconic nature of the speech.

By no means am I arguing that these words literally tore down a wall. But if anyone can argue that a speech can ever be important, this one was, at least for American culture.

So my point here is that this author is punching at a straw man. I don't know anyone who believes this speech itself contributed to the felling of the wall. It was an event in a much larger storyline that was bigger than the wall itself: the cold war.