The level of fashion "elitism" shown by some of the posters is surprising.
I agree. My choice of what to wear is an expression of my feelings/mood/necessities/ or whatever. I never dress on account of what folks expect me to wear.
When I want to send a message that I think the situation is important to me I may dress up. For the record, going to an Opera would not be such a situation.
Or you can't make a silk purse out of a sows ear. Ever heard that one?