Does effort in observing tznius guarantee parnasa?

 Rabbi Eliyahu Falk writes in the supplement to his book on Modesy page 38.

It should be noted that in the merit of mesiras nefesh for Tznius the community at large is blessed with sustenance and parnasa. See Berachos (20a) where the Gemora presents a question: "Why is it that as soon as Rav Yehuda removes a shoe  (as he prepares to pray for rain) it starts raining right away, whilst we pray and pray for rain with no response?" To this the Gemara answers: ... The earlier ones were moser nefesh for the sanctification of Hashem's name. For example, Rav Yehuda took the courageous step of ripping off a woman an outrageous cloak she was wearing ( which could have brought him dire trouble from her husband and family) in order to eliminate the scourge of pritzus from amongst the Jewish people. They therefore merited to have their tefillos for sustenance answered. We, however, have not shown mesiras nefesh on behalf of Tznius."

It is spelled out  clearly in this statement that rain, one of the most elementary substances needed for the preservation of human life, is guaranteed when people are moser nefesh for Tznius. Accordingly, women who change their inadequate clothes for adequate ones in spite of the enormous bother and expense involved are to be envied for in their merit Klal Yisrael is blessed with ample food and parnassa (provided they pray for it).

I am having great difficulties in understanding how Rabbi Falk derives his conclusion from this gemora. The gemora - which I have cited in full below - says that prayers are not answered for contemporary generations - despite their much greater knowledge of Torah because they don't have the mesiras nefesh of previous generations. The example of mesiras nefesh the gemora gives is that Rav Adda ripped off a garment from a woman that he considered immodest. But the gemora notes that the woman was not Jewish and that because he embarrassed her by uncovering her hair (which was against the modesty of goyim at that time) he was fined 400 zuz. 1) There is no promise of paransa mentioned for wearing modest clothes, 2) The act of mesira nefesh described in the gemora of a man forcibly removing a woman's red garment - is obviously not something that Rav Falk would recommend. 3) Rav Adda was in fact punished for this by being fined 400 zuz. So how was this act commendable? Also this is not the halacha.

שולחן ערוך (יורה דעה הלכות נידוי וחרם סימן שלד:מח

אם נידו לאדם אחד על שעבר עבירה, וגזר השר עונש על מי שיחזיק הנידוי, חייבים ליכנס בספק עונש כדי להחזיק דתנו. אבל אם נידוהו על דברים שבינו לחבירו, כגון שהוליכו לערכאות של עובדי כוכבים, אין אנו חייבים ליכנס בסכנת העונש. הגה: וע"ל סי' רכ"ח גם סעיף מ"ז וגם בסימן רל"ב סעיף י"ב. אף על פי שחייב אדם למחות בעוברי עבירה, וכל מי שאינו מוחה, ובידו למחות, נתפס באותו עון,  מכל מקום אין אדם חייב להוציא ממונו על זה. ולכן נהגו להקל מלמחות בעוברי עבירה, שיש לחוש שיהיו עומדין על גופנו ומאודנו (מהרי"ו סימן קנ"ז).

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Berachos(20a): Said R. Papa to Abaye: How is it that for the former generations miracles were performed and for us miracles are not performed? It cannot be because of their [superiority in] study, because in the years of Rab Judah the whole of their studies was confined to Nezikin, and we study all six Orders, and when Rab Judah came in [the tractate] ‘Ukzin [to the law], ‘If a woman presses vegetables in a pot’ (or, according to others, ‘olives pressed with their leaves are clean’), he used to say, I see all the difficulties of Rab and Samuel here and we have thirteen versions of Ukzin. And yet when Rab Judah drew off one shoe, rain used to come, whereas we torment ourselves and cry loudly, and no notice is taken of us!He replied: The former generations used to be ready to sacrifice their lives for the sanctity of [God's] name; we do not sacrifice our lives for the sanctity of [God's] name. There was the case of R. Adda b. Ahaba who saw a heathen woman wearing a red head-dress in the street, and thinking that she was an Israelite woman, he rose and tore it from her. It turned out that she was a heathen woman, and they fined him four hundred zuz. He said to her: What is your name. She replied: Mathun. Mathun, he said to her: that makes four hundred zuz.