If Lucas has personal, petty revenge reasons behind his artistic decisions, then hey, y'know... that's the reason behind it.
Maybe the divorce emotionally traumatized him so he intentionally made the characters in the new films unemotional blankstates to piss on the audience, his old co-workers and his old feelings while making a shitload of money? not a defense of the films, but hey, a pretty cool story as such :D
Btw, Marcia kinda looks like Lucas in that profile shot... `^_^´