Even if I'm super comfortable with social nudity, I can understand why some people are extremely modest or simply don't like to be in social nudity environments. I respect that and don't try to force my way of seeing things even if I don't agree with yours.
A psychologist explained to me once that there are a few reasons why some people are very modest regarding nudity:
One, it's about insecurities, self-esteem and body issues. We're constantly bombarded with images and ideas of how we should look like, if we don't fit that ideal, we feel less and judged. I think we all at some point had suffered from that at some degree.
Second, social beliefs and cultural or religious views on nudity. Some groups still see nudity and sex as the same thing, or a nude body as something dirty or private that only your spouse should see in certain occasions. Also, some men avoid being nude in the same space with another nude man because they feel it's gay.
The third reason is more complex and deep within our mind. Because when we are nude we feel vulnerable, physically and emotionally, that can trigger some fears and traumas in some people, especially from childhood or adolescence experiences.
