Motif, along with X11 is just completely obsolete platform. (btw, this is what UHH thinks about it: "What Motif does is make Unix slow. Real slow.")
There's some weird GPU hate in this thread that I don't quite understand. Try to render dragging content of 1080p window at 60fps on cheap mobile ARM core, and you will likely blow your whole time budget just on filling the window with solid color...
You should look at GTK+, motif, or TCL/Tk. They're very straightforward and don't turn people's devices into hand warmers.