Sure it might very well be burn out, the stress anxiety depression can weigh a person down.
Now we have other problems to contend with.
Sometimes I think the embarrassment of being a JWS could be another factor.
In reality the WTS/JWS is just an endeavor by men who were seeking out their own power and personal stature and they found that they could accomplish this by using/exploiting the general public's belief in the bible and of God.