Makes sense ---I'm right handed so if I reach for the X handle I'm mostly on that side of the machine. I don't thing there is a wrong answer.
It's interesting you mention that. My left eye is the dominant and I'm ambidextrous. I chose the right side because that's where the electrical boxes are on the machine, and there was more free space on the right than the left. The left side already had the light.I'm guessing that it might depend on your dominant eye, I don't have one now, but when I did, it was on the right side.