I don't buy this - if you add a feature to software you know it's going to get used - if they needed it for internal stuff they could add it in some private library.
And, if it's something people want so bad that you'd allow it for non-published applications then you clearly need to solve it by enabling or offering some sort of replacement for published applications.
The underlying API is a decade or so older than the current version of the human interface guidelines. It's entirely possible that if they were writing the API today, they'd leave that capability out.
And, if it's something people want so bad that you'd allow it for non-published applications then you clearly need to solve it by enabling or offering some sort of replacement for published applications.