I read that article yesterday and I had the same reaction. It sounded like someone who hasn't been in the real world for very long. Dynamic typing is a ton of fun to work in, it's so fast and easy, and then you get on a big project and there's a weird edge case bug that no one can ever track down and it's because a typo allowed something to instantiate a new variable in a corner case that unit tests missed, and no compiler would have let through. Yay.
Yawn.
I think you wrote a good response here, though I hope it isn't needed. I really want to believe that anyone who read the original post and took it seriously isn't in a position to be making those decisions on any substantial or consequential project. I know I'd be wrong, but I want to believe. :D
J.Ja