Its really about striking a balance between, on the one hand, people respecting each other's feelings and, on the other hand, people being tolerant of each other's choices, isn't it?. In a diverse society like the US, there are so many ways people can offend each other's sensibilities. I suspect that is why the US Constitution so carefully protects minority and individual rights unless others are actually harmed. At the same time, over the years while working in the States, I have seen the definition of "harm" and "offense" get kind of muddled together, the latter often becoming legislatively the former when an organized group is convincing about its electoral clout. It can be a sort of backdoor imposition of majority preferences on minority rights which undermines tolerance.
Choosing not to wear clothing, as Mark points out, does not in itself pose a threat to others. Forcing someone to dress a certain way is in fact the aggressive behavior. Why shouldn't we demand a little tolerance? It is hard to understand why people, particularly nudists, have not objected when legal adjectives got mashed into their nouns -- for instance, when did "exposure" become "indecent" by definition, rather than "indecent" being a specific subform of behavior. The real danger, as Mark again rightly points out, is when a peaceful minority acquiesce to marginalization, thereby relinquishing their right to tolerance by the majority. We nudists may find it "a trifle absurd" or even disturbingly incoherant for people to go swimming in their clothing, but we tolerate it -- as they should tolerate our decision to leave our clothes safely dry onshore. If they want to sweat in clothes when sunbathing, we don't require them to hide behind fences, nor should they us when we are acting more sensibly. I bet our families could even picnic next to each other in a public park without misfortune to anyone!