It's a non-issue for me, but I do understand back problems. Being 6'3" I prefer my workbenches and shop equipment to be taller. Otherwise, my back starts to ache and get stiff.
However, with the planer you are not bending over for more than a few seconds at a time. Usually, you can stand up straight while it feeds itself through the planer. Out feed support might help with long boards, though.