What has happened?

What has changed within the greater American culture so that kids today seemingly have a very false sense of modesty? Kids no longer shower after gym class at school. They are “afraid” to change (totally down to being naked) clothes in front or other same sex classmates or even strangers in appropriate places such as public pool changing rooms etc. I don’t get it. When I was young, all us boys (men too) swam naked at the YMCA—that’s how it was. Now most people in America are hypersensitive about being careful not to show any skin. I don’t get it. Can someone shed some light on this for me.