My wife has a posting (click link) on those who treat the mitzvah of hafrashas challah as some type of magical segulah, akin to wearing one of those red string things. Clearly, the mystical and magical have an attraction that plain vanilla rational Judaism does not – but I’ll leave the sociology to her. I will just add that poskim (Mishna Berura 242:6) advise that even if one eats pas palter (bakery bread) during the week, one should aim to eat pas yisrael on Shabbos and Y”T. This is one reason why the custom of challah baking for Shabbos developed (and my wife does a good job spoiling me most weeks with home baked challah and cake).
My wife mentions the three mitzvos (nida, challah, ner shabbos) that are the “women’s domain”. There is much to say on this, but very much b’kitzur, the cheit of Adam created a ta’aroves of tov/ra that requires birur, separation, in order to correct. The common denominator of these three mitzvos is the idea of separation. The three mitzvos correspond to the classic paradigm of olam (matter), shanah (time), and nefesh (soul): ner shabbos represents separation in time between kodesh and chol, challah represents the separation of matter into kodesh and chol, and nidda represents the separation of the nefesh, the husband-wife unit, from itself. Why this tikkun was given to women and how it works is for another discussion, but for those who want some homework: see Rashi on the pasuk where Rivka enters the tent of Sarah after joining Yitzchak and you will find a parallel between the three miracles of the imahos tent and these three mitzvos.