It think that they are basically asking "If this is not the truth, then what is?" "What will I use to fill that place in my thoughts that were occupied by the WTBTS teachings, since i have been taught that every other belief is false"
This is the point..... once you have found that every other belief is false and use that same method on the Watchtower society. Then you are left with only one option. All religion is false.......their is no God.
Therefore where else should we go is a fallacy, cult speak.....MIND CONTROL. Free your mind from this type of thinking its remnants of mind control.