[aerohead]

I'll take a stab. There might be an overall advantage,minimizing un-sprung weight,by moving the mass of the motor(s) inboard.
The hub-motor would make for a rather large pendulum,with increased stresses imparted to all the suspension components,plus chassis attachment hard-points,requiring more massive parts and adding to overall weight,all mitigated if this mass is re-directed inboard.
Oilpan4's comment about a wash-boarded road evokes visions of a torture chamber for bushings,springs, dampeners,and chassis.
I tore a shock tower off my VW bus on the Kananaskis Trail in Canada.