I'm yet to be convinced they'd be useful for anything.

Other than, perhaps, signing on to a competing project to bring it down as well.

But they've made gnome worse, not better.

Worse for some people and better for other. My mother (58) and my grand mother (82) love how easily is to do what they usually do contrasted to the windows 8 experience.

I don't know if that is a common case or not, but at least it's not a definitive "worse" or "good". And for me, it's great as I never got a call to ask me where is something anymore.

Well, my little sister (12) and my dad (56) love KDE Plasma, as it’s "simpler than windows".