Of course, should have realised that. It may be effective and good to use, but it does look a bit odd; there again I was only 'walk on freight'.
I remember during training on the 'pig', a certain pilot landing in a strong breeze checking out all 4 extremes of the yokes axis. He was sweating by the end of the landing run.
I guess a joystick would have been much easier.
A side stick does not necessarily make flight control less physically strenuous. Assuming the same fly by wire flight control system otherwise, using a yoke as the "input device" would be equally non strenuous as a side stick.
For the C-17 specifically, a center stick was mandatory. Unlike Airbus airliners, the C-17 has a "manual reversion" mode where the pilot controls the aircraft with old fashioned cables, pulleys, and push rods. That's just not possible with a side stick.