I think the point you're making is that orientation of the image is arbitrary, and the original commenter agrees that's the case for one eye: "If we had only on

I think the point you're making is that orientation of the image is arbitrary, and the original commenter agrees that's the case for one eye: "If we had only one eye, there would be no issue, the image would appear as a continuous image, just flipped around." But we have two eyes, so if you directly connect the two inverted images observed by each retina, there would be a discontinuity in the middle of the joined image (peripheral light from the outer sides of each eye would be mapped to the middle of the joined retinal image). The original commenters point was that criss crossing the neural connections from the retina would resolve this discontinuity, allowing the brain to process a continuous image.