This is in response to flatbush27 comment: ” its just not how a Bas Yisroel acts even on Purim”. I accidently posted it earlier in the wrong thread.
Alcohol breaks down the boundaries of modesty much faster than costumes that are inherently modest. If you ban women’s costumes, I would argue to restrict alcohol from women to such an extent that “sipping from the Kiddush cup” would only be barely permitted. Even the author of a very stringent book on Tznius (modesty) permits “loud” clothing in cultures that this is the norm. On Purim loud (but modest) clothing are the norm.