Besides KDE and GNOME (and some GNOME forks like Cinnamon), none of the other choices are particularly close to a decent full desktop experience. They are generally either limited in nature or require you to be one of those people that likes to dig around for hours cobbling together scripts and adjusting the minutiae of scattered, poorly documented config files exactly to their specification. I have certainly done all those things, but of all the people I know nobody else actually wants to basically fight with their machine like that. They would rather want a useful suite of easily discoverable applications that they can use right now, and a couple ways to personalize their machine in a cosmetic manner.