Oh yes, it may well be in one's best interest to simply move on from here, pro or anti-jw, or some mix thereof. Quite a few have come and go, and for them, this board served its purpose, and they've moved on.
Many however stay even though they have essentially moved on with their lives. They've made friends here, and use this DB to keep in touch. Some post mostly to fluff threads and simply enjoy hanging out here. I don't think that's in any way unhealthy.
Still others feel they should stay and lend a helping hand to newer posters. And many still need to be helped, comforted, and supported in their decision to leave the jw religion.
So there are members here that are in all kinds of stages as they move away (or stay with) the jw religion. I don't think that its unhealhthy for such people to remain here as long as this board continues to fill their needs.