Having been around for quite some time, and having used several dynamic languages, my pet peeve isn't types.

Rather I prefer not to be in the same spot I was in 1999 - 2001, with Tcl, and every now and then rewriting code into C, for the application to actually deliver within the performance deadlines.

Python is the only mainstream dynamic language where runtime support for dynamic compilation is such an hassle, where the alternatives do exist, yet are mostly ignored.