Gnome UI sucks. It is ugly and non-customizable without plugins, or whatever you call that addon that enables you to put your clock on the right... I'm sure the UI makes more sense on a tablet or a phone with touch controls, but I just want to use it on my laptop with a regular monitor and with a mouse (or touchpad).
KDE has sane defaults and looks and feels like Windows UI from the best era. It just works.