There is a website called jumptheshark.com in which people debate the exact point a TV show started to go downhill. Why not apply the same concept to forum posters?
Smeg: Agrees to hotseat interview with BKKPhil. People didn't know if Smeg was for real, a single poster, or just a clever troll. After we learn (somewhat) the truth about him, he just isn't as menacing a figure as he was before.
Captain Sensible: Finally arrives in Thailand. His post count drops off and seems to lose interest in the forum. The controversy surrounding his encounters with other posters you can read in the Members Forum.
Smiley: Becomes a mod at ajarn and starts deleting posts from people he sees as troublemakers. The final nail in the coffin that led to the permanent split in the ajarn forum membership.
Biohazard: the first time he posted a response on a forum.
Daisy/Soph: Gets married. Probably finally came to her senses and realizes she is spending too much time talking to us weirdos.