> I have my own data point in this discussion. Back in May, there was a long thread on Emacs-Devel about removing ns-do-applescript from the Next Step branch. The problem, according to the instigator, was that applescript runs only on macOS which is not a free operating system—although it does represent over 25% of Emacs users—and therefore ns-do-applescript should not be in Emacs.
This isn't the first time that free-software spite has led Emacs developers to disable perfectly good features. Back in 2016, Emacs developers deliberately prevented color emoji from being displayed on the macOS port because Linux (and other free software platforms) didn't support color fonts at the time.
Emacs is a GNU tool, right? Why should they be forced to merge patches that don't relate to the GNU software ecosystem? Adding Applescript compatibility means that contributors who maintain that code require proprietary hardware to fix these issues. The GNU project forbids members from spending donation money on proprietary hardware, even for debugging purposes. You're better off asking why MacOS doesn't have support for EXT4, just because "all the work is already done for them"
If color emojis and Applescript compatibility is such a huge deal, the license explicitly allows you to fork Emacs with these changes merged. Knowing MacOS developers, they'll probably even charge you for it too (which the license graciously permits as well).
There already is a fork of Emacs for MacOS, which I and others on this site have been using for many years (me since 2010) because this isn't the first time the Emacs project has neglected or outright sabotaged Emacs on MacOS:
https://github.com/railwaycat/homebrew-emacsmacport
One time (roughly 2012) FSF Emacs was in such a bad state that you couldn't interact with it at all: it would display as small, un-resizable window, but nothing I did would cause anything sensible to appear inside the window.