I'll take a wild guess. The reason can be Objective C. The language and its framework is fully dynamic. Your program can compile, but without extensive testi

I'll take a wild guess. The reason can be Objective C. The language and its framework is fully dynamic. Your program can compile, but without extensive testing you won't know if it works. Checks that statically typed languages do at compile time have to be done by runtime tests in dynamic languages such as Objective C. And Apple doesn't have the ability to do enough testing for their products to ensure every single feature is bug free.