I, and basically every language designer since the 80s has disagreed with this. It's needless repetition: all of the information contained in the .h file is duplicated in the .m file. If you really want a nice listing of the exported methods, it's easy to generate that from the .m file.
I agree that there is some merit in the repetition argument, but when discussing a language like Objective-C we must consider that any Objective-C programmer is surely using auto completion to the fullest extend due to the extremely verbose nature of Objective-C naming conventions. The point being that the repetition time is negligible
It is incredible how C based compilation models become so widespread, that younger programmers are completely unaware of sane module systems in other languages with ahead of time compilation toolchains.
