And that's an argument? Why not include static typing, or single inheritance, GOTO while we're at it? I'm sure there are those who happen to like them.
Well if anything, this is one of the most vocative trolls I have ever read. :)
Why is static typing in that list? Unlike single inheritance or GOTO's, static typing is a good thing. Dynamic typing is often used in interpreted languages because once you're writing an interpreter, there's going to be a massive performance hit anyway and dynamic typing won't make it a lot worse. Dynamic typing makes compiling efficient code very difficult.
Of course, a good static typing programming language should have at least some kind of type inference mechanism to allow the programmer to leave out explicit type declarations when a compile can infer them from the program source code.
Boo is a statically typed, type-inferring language for the CLR that has a Python-like syntax. It seems pretty nice, I've written a few toy projects with it.
Examples: static typing with optional duck types: Boo. dynamic typing with optional type annotations: many Lisps, e.g. Racket.
One benefit is additional optimizations. Many good Lisp implementations take advantage of this.