[Udo]

It's debatable whether this behavior was a good fit for Objective-C, since it's not actually a dynamically typed language. People reasonably expect their Obj-C compiler to do static checks and in this context dynamic behavior is an unwelcome surprise. It would be interesting if, for example, Smalltalk developers share the same frustration. My guess would be: probably not.

My go-to example in favor of the idea would be languages and libraries where 'null' and 'empty list' cause the same behavior in list-processing functions.

[cballard]

Objective-C is definitely dynamically typed, feel free to use "id" and go to town. To say nothing of swizzling.