> ... its actually good sense.

It's only "good sense" if, and this is a big if, (a) we have a strict scientific understanding of what we mean when we say "unclean" and (b) we know that we have literally no other way of mitigating this "uncleanliness."

Just as surgeons learned to sterilize themselves and their equipment once they had a scientific understanding of infection, we now have lots of scientific understanding of human menstruation and cleanliness. We should therefor look upon those that insist that women be treated as "unclean" and kept away from the village water supply and temple the same way we'd view a surgeon that insisted that there was no need to wash up before operating.