The reason sex/nudity is considered offensive in this country is because our collective moral code is based on chirstian ethics. Althtough not all people believe this as a whole, as in the majority, of people have a cultural belief that sex/nudity is offensive/wrong/sinful. The reason authority(gov't and religion) is control, they want to control reproduction, and pretty much every other part of the lives of the people. THat is why, religions especally, create so many rules about proper sexual contact and nudity.
P.S. someone mentioned that Michellanglos david was covered during the middle ages, which is inpossible as it was created during the Renainance. Now it was covered during the victorian era, which is when the also destroyed/defaced many classical works, like the wall frescos in Pompeii.
And also wisdom teeth are a problem of softer diets, forager groups rarely if ever have problems with widom teeth, but they eat a much tougher diet and their jaw grows to accomidate wisdom teeth as they have a need for them.