I. M. Shluffin, DY, FNY – Unfortunately, R. Falk’s book has proven to be a Michshol for many women. Similar to Chava and touching the Eitz HaDaas, they (correctly) believe this is not Halacha, and therefore (C”V) Tznius is entirely made up by men to control women, so there is no need to hold of it.
The concept is certainly a good one, and a bad application should not ruin the idea. What should be learned are the sources INSIDE. Learn the Rishonim on the Gemaros in Brachos & Kesubos, Shulchan Aruch, Meforshim. Not a “Pamphlet” or “Book” that will only make people think the whole thing is fake.
And yes, Tznius is much worse. A strong possibility (IMHO) for the reason is that Tznius is being taught by rote, from Pamphlets and Books instead of sources and real Halacha. The way to make it stick is to make it real.