The problem isn't that they accommodate touch screens, but that they do so at the expense of keyboard and mouse users, and then they push these changes to GTK in a way where keyboard-and-mouse interfaces become clunkier and GTK-developed UIs become very hard to integrate with other desktop environments.

Firefox has definitely been affected by this. The hamburger button is a touch paradigm which makes no sense on a large desktop screen with a mouse and keyboard-control scheme. It only serves to add more clicks to every interaction. Likewise the reduction of the scrollbar to a scroll indicator.

I was sad when Gnome 2 became Gnome 3 because I really liked Gnome 2 and Gnome 3 was broken. Then I moved on, but where ever I went insanity from the Gnome project kept leaking and making UIs worse.