An ad hominem, is it not?
You have a right to move about in public, without having to view others' private parts, even if thinly veiled. If you want to call that a dress code, go ahead.
These are the "thinly veiled private parts" in question:
I'm sure you could guess there's a pair of buttocks in there somewhere...
Of course, Merriam-Webster defines dress code as:
"
DRESS CODE: formally or socially imposed standards of dress"
These are standards of dress, and these people are formally imposing them.