What a horrible thing to say. You're being insulting to someone who is trying to contribute and you're totally missing the point. We try to be better than that here.
While his wording is a bit blunt, specific attires can cause disrespect and discomfort among staff. When a workplace doesn't enforce a dress code, I assume it expects its employees to be self governing.
I am not convinced that baggies and a hoodie convey responsibility and professionalism, as befitting someone who has been given a free reign to dress as they see fit.
What a horrible thing to say. You're being insulting to someone who is trying to contribute and you're totally missing the point. We try to be better than that here.