LOL. This is something I've seen for decades. People have been trying to push the boundaries of good taste in casual attire at work and then complaining about others to protect their delicate eyes if they don't like an individual's look. Locally this seemed to happen more after the creation of "casual Fridays" From flip flops, to halter tops, to spandex, daisy dukes, belly shirts, sprayed on jeans, yoga pants, political, provocative message, non-company brand t-shirts, tank tops, stripper spike heels, etc etc. yes there are many that dress more provocatively than they should. There are also some that look really good in those outfits, which curiously rarely seemed to get as many complaints, well, at least by males.
That said, for the companies I've worked for that had these issues (most of them), the fix was simple. Detailed dress code that every employee signed. If they ignore it they get sent home to change into something more appropriate. they don't get paid during that period, so they have to make the time. Everyone was told, if you're not sure it's appropriate, either ask first or bring an alternative along you know is acceptable to avoid problems. There were always a couple stubborn fools that insisted on testing the policy early but they either got with the program or left the company.