> It's always, "If someone else sees nipples, it will harm them."

... I find it more compelling to put it this way: "If we make [something currently seen as sexual] normal in public, it will harm society".

There isn't anything more magically sexual about the nipple than there was about the thigh. It's an arbitrary line in the sand. Culture/advertising has exposed the fact it's arbitrary by pushing up against it, but maybe it's just as sensible to argue that the line should move back towards being more modest than being less so.

There is a separate discussion about why women's norms are more restrictive than men's, but I think things have gotten more libertine across the board.