I don't know who you've been talking to, but that's ridiculous. C++ is one of the most widely-used languages for writing native apps for any OS. Adobe products, Chrome, anything built with Qt, even the Swift language itself, all made in C++.
Adobe products have codebases going back decades, of course they are written in C/C++. Furthermore most Adobe apps have fairly advanced processing needs that your run-of-the-mill CRUD GUI does not.
> anything built with Qt
Qt isn't even stock C++, they had to hack a meta-compiler on top of C++ to effectively serve the needs of their GUI system.
> even the Swift language itself
By this logic, thousands of GUI apps are written in x86 assembly.
Between C#, Objective-C, Swift, JS+Electron, Mono, and many other mature, high-level frameworks that don't trash memory at the slightest provocation, youd need some very good reasons to use C or C++ for a GUI app these days.
Secondly, compilers are a very different programming task to developing GUI apps; the Swift team choosing to use it has nothing to do with Apple’s assessment of how you should write an application—Apple are the people who have been leading objc development (they own the objc IP) in the last 10 years and use it in all first party apps and many system frameworks.
> Many of the low level libraries in OS X and iOS are written in plain C for speed and simplicity.
And don't forget that OSX/iOS are based on Darwin BSD, where most of heavy lifting is done by programs written in C.
- [1] https://developer.apple.com/library/mac/documentation/String...
And internally apple use other languages a lot, but frameworks like UIKit, AppKit, and many of the other public frameworks they expose in the SDK are objc, with foundation for example abstracting a lot of CoreFoundation C code.
That's not a knock against anyone who does or doesn't write apps in a particular language; but folks should know what the reality is, and Objective C or Swift are by no means the only or even necessarily the most profitable ways to writes apps for OSX, though those languages are perfectly fine for many circumstances.