I believe even in the context of mathematics orthogonal means independence. I.e., one can move along x and y axis without having y or x value being changed. However if you move along any line that's not parallel to x or y axis then both x and y value change simultaneously. That's how I interpret orthogonality in the context of math anyway.
As long as you don't rely on concepts that don't generalize to higher dimensions. To the extent that you use concepts that don't generalize in your example, you are using a poor example.