You know, as I think about it more, I believe it is more a matter of people not having any idea of how to dress, at least a majority of them. At one time, most people had an idea of the appropriate level of dress for an event. In recent years, either people are not taught that, or they just don't care. And of course with the general casualization of society, even the rules from days past will have changed some.

Perhaps what more people need to do is specify the level of dress in invitations, rather than assuming everyone will know what is appropriate.

As an example of how things have changed, I saw an old episode of the Andy Griffith Show the other night. Aunt Bee had won a trip to Mexico and everyone was at the airport to see her off. All the men and boys had on their jackets and ties just to see her off. My, how that has changed.