A lot of biplanes are flown solo from the back seat partly to put the "optional" front seat load closer to the CG, but mainly because (despite what you might expect) the view is generally a lot _worse_ in the front seat, with wings above and below blocking your view to the sides. In the back of the Tiger Moth, Stearman or Stampe you have a much better view of the ground, and of the air you're turning into, than you do from the front.