Part of the problem with mainstream acceptability of nudity, is that (most) nudists want to remain segregated. It's like the blacks in the 60's saying: "we want to ride in the back of the bus!"
Actually, I want to be able to ride anywhere in the bus, and why not? It's the same premise for nudist beaches, which are closed on a regular basis, and even the "permission to be naked in this one spot", (the back of the bus), is removed for the people by a single puritan hysteric. We should insist on the right to be naked on any bus, and anywhere in any bus. Or beach. Or anywhere.