The work load was a huge factor. I actually had an emotional break down of some sort. But it was this hitting "rock bottom" that woke me up to the fact that I needed to address all of the doubts that I had been suppressing for most of my life. I think that if the work load had been very light, I would have gotten comfortable and complacent, and never looked into all of the beliefs that had been eating at me for all of those years. But it was definately the endless, exhausting treadmill of "salvation by works" that eventually caused me to completely burn out and to fade out.
Is this over-working of the friends deliberate and by design? I believe that the answer is both yes and no. Let me explain. Do any of you remember the well-known illustration that was used often in talks of the fence? A brother would describe the meeting schedule as a fence with five cables on it. ( five meetings ) He would usually draw a picture of a fence on a black board and would take an erasure and erase one cable at a time saying: "Look friends, don't you see that erasing just one meeting from the schedule weekens the fence that separates us from Satan?"
This illustration was quite powerful and made people refrain from ever complaining about the schedule. I believe that the Society truly believes that it is their ordained duty to "corral" the friends in to protect them from Satan. I think that they truly believe that keeping the friends extremely busy is the only way to protect them from "worldly influences".
To illustrate, I have heard of parents who were so terrified of their children getting germs and viruses, that they would force their children to engage in the most incredible rituals of cleaning, washing, and bathing. Often; the child because of being indoctrinated, becomes so terrified of germs, that he doesn't think twice about the rituals.
Some parents because of having irrational fears and faulty information will do some very irrational things in trying to care for and protect their children. Some children fall in line and become comfortable with the behavior. Then, there are those few who revolt.