Many have moved on because JW stuff stops being interesting after being out for a while.
Then there are those that have left after being "offended" at being unable to defend their ideas. It's always interesting across the many forums I am present, one side calls for censorship of ideas and if the moderators agree, you get an echo chamber and if the moderators aren't censoring, they leave in protest instead of engaging in discussion leaving behind an echo chamber.
There are still interesting conversations around here, but the world has been changing as have conversations in the world, I can't believe people that left the JW mindset are now simply re-accepting similar ideas of collective guilt, group division, religious creeds and groupthink in politics.