They did have a procedural API, it was called Carbon; which was a nearly drop-in replacement for the Macintosh Toolbox API that user32.dll blatantly copied. Th

They did have a procedural API, it was called Carbon; which was a nearly drop-in replacement for the Macintosh Toolbox API that user32.dll blatantly copied. The thing is, outside of programmer fuzzies, UIs really, really want to be object-oriented. A tree of unrelated objects sharing some common behaviors describes basically 99% of all UI code. And Toolbox / Carbon really strained for lack of having one. That's actually the one original thought Windows added - window classes. Personally, the weirdness you feel manipulating Obj-C classes directly from C is how I feel any time I have to define a window class or procedure in user32.dll code[0]. OOP wants dedicated language features, just like how UI wants OOP. You can make do without but it's 2000x less ergonomic. [0] Or anything to do with GTK/GObject.