>>105760041Canonical dropped Unity 7 for Unity 8 which was Qt-based and was going to be their DE for desktop and phone platforms and run on top of Mir, their custom made graphical server.
The reason they dropped GTK in favor for Qt for Unity 8 was that GNOME devs were removing features and introducing a lot of changes that forced Canonical to patch all their GNOME apps (Nautilus, Evince, Rhythmbox, etc.) That was not cost-effective considering the release cycle of Ubuntu releases. Thus, moving to Qt and writing the apps from scratch was preferred.
The community HATES Canonical, Red Hat HATES Canonical. The result was that shills were in full force attacking all these projects and spreading FUD. So much that Intel dropped support for Mir from their drivers altogether. The project couldn't continue under such circumstances, Canonical had already lost millions of dollars and years in development, going back to Unity 7 would result in costs too, so they decided to just cut their losses and go back to GNOME. Still, Canonical managed to fix a shitload of bugs and memory leaks (the GNOME devs took the credit for all of that.)
Even today you can see shills pressuring Canonical to drop their tech and replace it for Red Hat tech instead. They continually call for Canonical to drop Snap and AppArmor for Flatpak and SELinux ("the standard" as they call them) which is the exact same playbook they used for Unity, Mir and Upstart.
Oh, and the beauty of Unity was that it managed to integrate GTK2, GTK3, Qt3, Qt4 and Qt5 programs seamlessly and they all worked with the global menu and HUD. It was GTK3/4 and GNOME specifically which broke the thing with their CSD and their nonstandard menus. GNOME devs designed it purposedly so it couldn't integrate with non-GNOME apps.