This is a rather empty statement as all these apps and the whole platform still continue to be open source.
>Call it what you want but they certainly don't intend to play nice with anyone and have adopted the approach of "my way or the highway"
I don't see how this is any different from how it was before. I've also found that KDE apps don't really work well outside of KDE, XFCE apps don't really work well outside of XFCE, etc. There is a clear line where an app developer has to decide if they're making a cross platform app (like LibreOffice, Blender, etc) or if they're making an app that integrates with a specific platform. Every single desktop I've ever seen has drawn this line somewhere because this is what users want, a KDE user prefers to use the KDE file manager and finds the GNOME file manager not so usable, a GNOME user prefers to use the GNOME file manager and finds the KDE file manager not so usable, etc.
>Most GTK4 apps won't be usable outside the intended desktop environment for which they're built.
I think you're confusing GTK4 with libadwaita, libadwaita is the library for GNOME apps that are only tested with GNOME and don't intend to be used outside it. GTK4 itself is not tied to any environment. And even then a developer could likely get libadwaita apps to work reasonably well in other environments with some porting work, similarly to how Krita depends on some KDE widgets and libraries but has been ported to other platforms.
>They also engage in carefully crafted doublespeak when it comes to things like extensions and user choice regarding configuration.
I don't understand, the stance on extensions has always been pretty obvious to me. Extensions are a third-party customization, they can work well and can do pretty much anything but because of that it's the user's responsibility to ensure their configuration is a working one.