I do hope the proposal is not to stop young women (or older ones, for that matter) wearing sexy clothes if they want to. What seems to be sticking in the craw of the new Mary Whitehouses is that that somebody is willing to pay women to appear at certain events looking sexy. So the Whitehouses are attempting not only to dictate what women wear, but to interfere in the operation of the free market.
Well, let's take this example: Hollywood been producing soft-porn films for fifty years now. Attractive young women are paid a lot of money to perform simulated sex on screen. Presumably this is to attract gawpers and oglers. Should we stop this because it is not consonant with the ethos and social norms acceptable to the Whitehouses?
Another example: what about the music industry which frequently goes even further down the path of porn. Here's an example:
https://www.arianagrande.com/videos
A lot of people with the same "ethos", but a greater sense of moral purpose might find that video extremely offensive. And who knows where thaqt could end up.