I did not see anyone here suggesting we implement the Sanhedrin’s treatment of women who display gross indecency in public (as described by the Chazon Ish.) They simply described the severity of dressing outside of halachic standards by noting the seriousness of the penalty in the time of the Sanhedrin. There is no reason to be up in arms. No one is currently collecting stones to make an example over the next prutza. Hence no one is suggesting this is a contemporary halachic issue, since there is no means of implementation. Hence this penalty not being recorded in Shulchan Aruch. Nevertheless, that does not neglect from its serious consequences, as the ultimate penalty imposed for this crime in times of yore surely demonstrate.
Nor do I see anyone judging anyone here. People are simply describing the consequence of such actions on a general note; not on an individual level (e.g. plonis bas plonis dresses badly.) As far as the claim that this issue should not be discussed, this is a halachic matter of discussion. On what basis can one suppress discussion of this halachic matter? Since when are we shy about telling what halacha wants from us? Where is it written that hilchos tznius are an exception? That you *feel* that way, is no anwer. I see no reason to hide this halachic discussion. Or even focus any less on it than the problem demands. By the way, gedolim often call a community tznius asifa (for both men and women) and discuss this problem in shul as well.