I personally would find it rather disconcerting seeing naked people everywhere, and not because of sexual reasons. I don't suppose I know the real reason, just it would make me feel embarrassed and uncomfortable.
... it's called socialization and your cultural mores. That's more or less all of it, though, barring potential environmental issues. If it actually became common in your society, it wouldn't take too terribly long for it to become just a thing to you. There's nothing deep seated to it, just familiarity.
As for the breastfeeding thing, y'all do realize there's (several) fairly simple means to cover up and continue breastfeeding anyway, right? If bared breasts are that big of an issue for folks, just offer government issued shawls or something. Prudes get to stfu, kids get what they need, everybody wins.