I find it difficult to detect a common thread that would not only capture me personally but a much larger population of former participants. Rav Eliyahu Dessler divided people into Givers and Takers. Maybe we are all Takers who found nothing worth taking. Maybe we are fundamentally rebuffed Giver wannabes. Each organization, Jewish or professional, exacts a serious financial commitment for which there is little return. Certainly synagogue fees have escalated to where it really is not a good consumer purchase. Medical organization fees usually run a few hundred dollars which is not really exorbitant relative to other professional expenses. JCC is really more of a consumer purchase of facilities and services while Federation expenses are to some extent voluntary. No, I think the attrition has more to do with the value of connectedness than it does of expense, with the exception of the synagogue where some of the fees can be daunting and to some extent interpreted as a form of extortion to purchase a Bar Mitzvah.
Since it is easier to write about me personally than to generalize in the absence of assessed data, I'll go that direction, with a reasonable assumption that what I experience and act upon, others experience and act upon. I used to attend Shabbat morning services every week unless I was on medical call or out of town. Now I force myself to go about half the time to my own congregation, make a few entrances a year at other congregations, some more to my liking, some not, and for the last few years have dedicated one Saturday morning a month to my recreation, usually in the form of a day trip. Guilt level = zero. Number of people who have tapped into my mind to assess this transition also = zero. And if they did, I'm not sure I could tell them. But as an observer I feel little connection to the Rabbi or the relative triviality of the comments, I have found the operations of the governance sometimes offensive and have other outlets to enhance my engagement with Judaism. Spending two hours enduring a series of Aliyah Sound Bytes does not measure up to what I could be doing instead, whether that be a schlep to Beth Tfiloh in Baltimore where I return with a shabbos that I could not otherwise duplicate or a day taking in the pleasantries of Hershey Park. Shabbos, or really a form of half-shabbos, has not disappeared. I do not write, service the car or use electronics as my form of reverence to the concept of avoiding melacha but I am not feeling any obligation to revisit some relatively negative encounters and impressions of synagogue leadership during limited time that I largely dedicate to myself.
For many years, as High Holy Day Torah reader, my very consistent observation was that the VIP olim had a generous generous handshake for embrace for each other but a perfunctory handshake for me from about half. The work that went into this for their honor was their due. Or they never quite captured Ben Zoma's concluding aphorism: Who is Honored? One who honors all living things Avot 4:1. And lets not omit USY which had its ongoing cliques that endure at a price. But they also have a leadership that excludes holding office kids who opt for being on the high school athletic teams on shabbos. They value obedience over talent. Before long they find themselves with neither.
So yes, the organizations have depleted numerically. But the people who depart for elsewhere or sometimes nowhere, as the much commented upon Pew Research report attests, take away talent and energy that could have been tapped but wasn't valuable enough or convenient enough to either seek out or accommodate once identified. Cloning more of the last generation's leadership mindset only invites more attrition. Reb Pogo's observation has been vindicated many times: "We have met the enemy and he is us."