To people who are young enough to have grown up with smartphones, Gnome is more familiar, I imagine. I absolutely fucking detest Gnome, and I don't understand emotionally why anyone would use it, but ... when I think about it, it does make sense that some people would prefer to emulate a smartphone interface on their desktop.
Does KDE even have native support for touch screens? Last time I tried, when I tapped on an input field, no on-screen keyboard showed up. Worked perfectly fine on GNOME.