Every desktop environment is a massive memory hog. Do you really want something minimal like xfce on a touchscreen?
I've been using openbox for over a decade. That's completely false. Xfce is not a memory hog. And it's not minimal either it's fully functional.
Gnome is a bloated mess of a thing and I hate it. Why would anyone want their desktop to use over 1gb of ram. I have a 32gb laptop and I still loath the idea of throwing away memory on such a bloated awful thing.
Running gnome on a phone. Yeah... No
SXMO is pretty minimal in that regard, but it doesn't force you to use the touchscreen. Can also navigate through menus via the volume buttons...