there are many former witnesses I have contact with, and few visit or post on sites like this. One of them visited for a while but didn't post. I visited a few several years ago but never posted until recently.
I think it's a mental thing, it really does take cajones to register on an apostate site, after all we've been told our lives. I think you can take the number of new posters here and figure the number leaving is exponentially larger.