Yes, I'm somewhat puzzled that static typing seems so important to some, while it clearly only prevents one class of errors (and depending on the language, even that only to some extend, e.g. it's still possible to initialize enumeration class instances with invalid values in C++). I'd have expected that Eiffel's pre- and post-condition or design by contract in general, would have gained more traction with those who care about eliminating possible sources of programmer errors.