Dynamic typing, the keyboard and the mouse

Dynamic typing proponents like to think that way: type errors are not frequent. It is therefore best to have a language that allows you to plug any object anywhere, and write tests that ensure your program is doing what it should, instead of restricting your choices in the first place.

Using a dynamic language is therefore like not-so-long time ago computers that had exactly the same plug for the keyboard and the mouse. At startup, if you plugged the mouse in the keyboard socket and vice versa, your computer did not emit blue smoke but it did not work either, and you had to unplug and swap the cables.

This was not user friendly. Dynamic languages are not user (where the user is the other programmer that has to use your object) friendly.