It has been on Swift and Apple's official documentation since the early days.

People keep forgetting that Objective-C also had a full stack role on NeXTSTEP.

And the same full stack approach was also a thing on Xerox PARC systems, which mostly failed due to mismanagement.

Usually ends well for closed source platform vendors when developers aren't allowed to come up with alternatives like on FOSS operating systems.

At least, as long as the platform stays market relevant.

Why? There's no particular reason why a language can't span low-level to high-level. C# is a good example of that: normally you deal with garbage collected objects and references, but if you need to drop down to explicit stack allocations, raw pointers, unions etc, you can - though of course the resulting code looks very different from idiomatic high-level code.