Shalom-
1) The people who have done some analysis of these kinds of things are Deena Zimmerman and Tova Ganzel.
2) Based on my doctoral research that dealt with the modern-day observance of taharat hamishpacha, I can say that there are a growing number of women who turn to Yoatzot and many find them more accessible and thorough than many rabbis.
There are Yoatzot who help women find kulot or to know why things are ok, and so they make observance more palpable. At the same time, my research pointed to the fact that because Yoatzot have studied this area so exactly, there are aspects of halakha, and sometimes chumrot that they raise, which were not always part of the common practice, but are raised as concerns because of their high level of knowledge. When Mr. Zuckerman asks if people are observing "correctly" I wonder if that is what he means?
3) Probably most of the women who are asking would still observe even if it weren't for Yoatzot, but they might have asked far fewer questions (especially because yoatzot offer both phone and online ways to get a question answered) or been more machmir on themselves without reason, were it not for the yoatzot.
Chag Sameach,
Naomi
Naomi Marmon Grumet, Ph.D.
Director, The Eden Center
