That quote is probably oversimplified, but well-travelled friends of mine have noted that cultures that go topless tend not to sexualize breasts the same way Americans do.
Often, it is all about the mystery.
I understand, but even cultures that show bare breasts more cover up something, and they still have an obsession with sex and pornography. Eurpoeans see more breasts on tv, but that is a form of soft porn. They and we have some nude beaches but women still don't go out bare chested every day, they wear similar fashions, and men still want to see them naked.
I just think the article's assumption that Americans are especially obsessed with sex and nudity was naive.