What you're saying seems to me the equivalent to saying "If a kernel driver is a critical part of your workflow and usage model, then then run far away, the kernel driver API is unstable and the driver maintainer might get hit by a bus." Because as I have said before, the shell extension API is really not similar to kernel's userspace -- it's closer to the kernel's driver API, in that you get complete access to the shell's internals, you can muck it all up and crash things if you're not careful, the API is unstable, you have to follow upstream closely to really take advantage of it... but if you do all that then it's a very powerful tool, and you can do things that are not possible in "userspace" (i.e. outside the shell).
And the fact is, the kernel does remove old and broken and unmaintained driver APIs. That's your prerogative to do to that, as it is GNOME's (and KDE's) prerogative to remove legacy APIs and features that are not pulling their figurative weight in usefulness. I'm not trying to convince you to use or trust GNOME, I'm happy that you're using KDE and it works for you. But I wish you would not say these falsehoods without an understanding of how GNOME is actually developed, because from my perspective the technical process is extremely similar to that of the kernel, and heavily inspired by it. So please don't forget, the apple never falls far from the tree. If you have some insights on how to plug this maintainer gap that you think GNOME is suffering from, then let's talk about that.