The fact that you can do everything in C when developing a Windows app always makes me feel all warm and fuzzy. Building up from the lowest-level primitives just makes sense.
Meanwhile, on MacOS, everything is an ObjectiveC Object, so if you want to write an app in pure C you can but it's about 1000x more verbose because you've gone an abstraction level deeper than Apple intended, and you essentially have to puppeteer the Objective C class hierarchy to make anything happen. It's incredibly icky.
I don't know why they can't rebase the ObjectiveC class-based API onto a basic win32-style procedural API (technically win32 is also "class-based" but it's minimal). It's part of why I don't see myself porting any of my C code to MacOS any time soon.
Interestingly, Windows has its own object-oriented API/ABI with COM (and later WinRT, which builds on COM). However, the MIDL compiler for COM interfaces produces headers that are consumable from C, both to use interfaces and to implement them: https://www.codeproject.com/KB/com/com_in_c1.aspx
As far as I know, this still works today even for WinRT, although the generated C struct and function names get very ugly because they have to include the entire namespace: https://stackoverflow.com/a/7437006/111335
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.
Meanwhile, on MacOS, everything is an ObjectiveC Object, so if you want to write an app in pure C you can but it's about 1000x more verbose because you've gone an abstraction level deeper than Apple intended, and you essentially have to puppeteer the Objective C class hierarchy to make anything happen. It's incredibly icky.
I don't know why they can't rebase the ObjectiveC class-based API onto a basic win32-style procedural API (technically win32 is also "class-based" but it's minimal). It's part of why I don't see myself porting any of my C code to MacOS any time soon.