If you grew up going to the theater/ballet/opera, you are really not in a position to judge how others dress, because you are unlikely to understand how unusually privileged your upbringing was. I have rarely been able to attend any such performance, and I think was lucky to take my children to such a thing just a couple of times when they were growing up. I'm happy you were able to do so, and I'm happy you can afford a large wardrobe. But not everyone can.