Probably not. But societal norms, even today's very loose norms about clothing, should have more influence on what some people wear. I enjoyed reading the part in the linked article about how men used to attend baseball games in coats, ties, and hats (not baseball caps). I despise ties, hate wearing them, and I'm sure others despise wearing long pants, collared shirts, or even shoes. But is there really no minimum standard?
The end of the article is well done.
Any well-dressed freshman should question Posner’s premise that, just because we can’t draw a bright line, no distinctions between acceptable and unacceptable are possible.
At a minimum, I hope we can agree on one thing: Teaching is a thongless task.