You say failed witnesses as if that is a bad thing I don't t personally think that is the case. To be a witness you surrender yourself totally to an organisations will and loose your ability to think for yourself. You regress and become immature in terms of your powers of reason since you have to accept teachings and not question them. To fail as a witness means to suceed as a human being. I was a good witness for 4 decades but I was not necessarily a compassionate or balanced person. After all it is not the hours spent on service that count 10 hours accosting waitresses and leaving tracts in launderettes cannot be equivalent to one 20 minute thought provoking conversation.
In addition whatever the name on the heading surely it is the wish and intent of the owner of the site that counts not what you or I think. This site allows a voice for all, it is not the site itself that constrains who should and should not comment. The organisation itself condemns on line discussion groups regardless of their intent. No witness should be posting on forums such as this one not because they are unwelcome but because they are not permitted.
Really it is not polite to make assumptions about the character and worth of others. Many have made a positive contribution to the lives of others since leaving and didn't count a second of the time they spent.