By necessity, communities (especially internet ones) need to focus on their commonalities. Otherwise, there is little cohesion and the drive to remain a community weakens. Ironically, I have even witnessed this in online communities whose explicit goal was to cultivate community for its own sake--such nascent intentional communities rarely seem to flourish. When members' interests diverge or evolve, maintaining the community becomes less useful, both for the persons with divergent interests and for any members who maintain their original reasons for joining.
Reuniting was intended to help improve relationships that were in danger because of couples' lack of awareness about conventional approaches to sex, and although the community has evolved primarily in the direction of addressing problems that may accompany porn use, its basis is provision of a certain solution. Fundamentally, the site is most useful for persons who are suffering (for whatever sexuality-based reason). If members manage to solve their problems (that is, either quitting porn or instituting a healthy approach to sexuality within relationship), it appears that they actually lose the commonality previously shared with other members. For some, especially those who may have built strong friendships within the community (or who are devoted to the guru (since we happen to have a very charismatic one here (thanks be to Marnia, as always))), the end of suffering is not necessarily the end of participation in the community. Either visiting has become habitual, or providing support to others becomes a new purpose. Those who move on are going 'by the wayside' only from the perspective of this community (although some 'healed' individuals return with occasional posts (Neil comes to mind, in particular)).
Alternately, it is quite probable that some who might succeed in solving their porn- or sex-based problems do not immediately graduate to that (perhaps mythical?) state of being 'ultimately satisfied in life,' and thus may not be able to contribute much useful commentary at all. For example, reuniting was instrumental in helping me move past the impulse toward promiscuity (and lesser problems with porn). Yet, having solved those problems, I remain rather obstinately unsatisfied with life in general, even though I am happy with / appreciative of how I now approach sex. The message to be understood from my story, then, is that one set of problems is always traded for another--hardly helpful, already widely available from (choose your favorite Buddhist outlet), and certainly not a vote of confidence for the idea that solving your sexual problems will free you to abide in wholeness.
This community exists to guide members along the path to healthy sexuality. It does not (and perhaps cannot, while still maintaining vitality) provide guidance beyond the attainment of health. At that juncture, the diversity of members' non-sexual interests, lives, cultural backgrounds, politics, ethnicities, economic status, etc. becomes a powerfully divisive force. Certainly it is sad to move away from the community (for those who feel they can no longer contribute), but there appears to be little point in remaining, regardless of gratitude for the support provided here. In short, successful efforts to change the purpose can produce two outcomes: 1) a new community with a different focus, likely different membership, and a different atmosphere, or 2) a loosely-knit community that gradually dissolves due to lack of focus/commonality.
Even superficial similarities in non-sexual aspects of personality and ethics may not be sufficient to ensure cohesion. For example, I think it is accurate to say that hotspring believes it is important to live with the Earth rather than on it, that she appreciates the insight that can be gained through ritual use of certain plants, that she finds a meditative practice to be most rewarding, and that she is skeptical about the claim to absolute superiority made by western medicine. I unreservedly share these beliefs, but nonetheless approach them from a very different perspective. I am unable to endow the Earth with true agency (specifically, motherhood), but I still believe that the only defensible lifestyle (as distinct from culture) is radically simplified and indigenous. I value sessions with the plants (or derivations thereof), but cannot see the states they precipitate as spiritual or in any sense 'other.' My meditative practice (if 3.1x/week can be called a practice) has lead me to substantially different conclusions than e.g. I am an object of consciousness' consciousness. I think western medicine has been useful in its provision of hygiene, antibiotics, vaccines, and emergency surgery, but that advanced life support is inhumane. I appreciate the capacity of traditional knowledge systems to add to medical practice--e.g. acupuncture and novel plant medicines. I cannot, however, avoid skepticism of other alternative therapies such as CST (beyond the effects of sympathetic physical contact and placebo).
I am somewhat distressed about my apparent inability to simply appreciate what are basically shared views. I clearly have considerable progress to make before I can be a more agreeable human...I suppose that in the meantime, it would be in everyone's best interest if I did not voice any further doubts. So in an attempt at positivism, I wish you success in creating the community space that you envision, and success for all those who are still working on their healing.