Some of them left for different reasons.
The tone of the board started to change a year or two ago. I know there were some personal attacks on a couple and they just got fed up and left.
Another thing I have noticed is the members who are posting seem to be younger. Not that that is bad. Just that some of the older posters may just feel they have less in common with the topics.
A few who felt they were being too strictly monitored started the "creepy board" (or something like that) so they could hold their own uncensored debates. Some of them, although I didn't always agree with their opinions, were fun. Even if I disagreed I always respected their points-of-view. Some of them do occasionally still pop in. I wish they would more often.
I am in a situation where my place of employment is in bankruptcy and the workload for the last year has been so slow that I spend a lot of time here. If the company folds and I lose my job, I will probably only pop in for a few minutes a day as opposed to the time I spend here now. (P.S. Don't feel sorry for me. I have worked 35 years and would love the free time to keep up with my house finally. Just holding on after all these years for the unemployment check.)