Static typing is useful if you are building some program for other people to run that you want to be reasonably robust. However, it does not work well with interactive programming. If I had to declare all the types every time I do something in Mathematica, I'd be severely annoyed for no benefit.

Common Lisp seems to be the best of both worlds, with dynamic strong typing in general and advanced compiler type inference that can correctly point out mismatched types in most cases in SBCL, leading to much easier time programming interactively.