[dmeb]

I haven't used erlang - that said, one reason might be that it's dynamically typed by default, and that the extensions for a type system have had mixed success:

"Phil Wadler and Simon Marlow worked on a type system for over a year and the results were published in [20]. The results of the project were somewhat disappointing. To start with, only a subset of the language was type-checkable, the major omission being the lack of process types and of type checking inter-process messages."

http://learnyousomeerlang.com/types-or-lack-thereof#for-type...